Erlang/OTP 28.0

This release of Erlang/OTP can be built from source or installed using pre-built packages for your OS or third-party tools (such as kerl, asdf or mise).

docker run -it erlang:28.0
Erlang/OTP 28.0
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Initial Release OTP 28.0
Git Tag OTP-28.0
Date 2025-05-21
Issue Id
System OTP
Release 28
Application
Potential Incompatibilities

Highlights #

OTP-19180
Application(s):
compiler, stdlib
Related Id(s):

PR-8699, PR-9094

For various error types, the compiler now tries to suggest potential fixes by adding “did you mean …?” at the end of error messages.

When a function is used with wrong arity, the compiler will try to suggest a defined function with the same name but a different arity. For example, given the following module:

-module(typos).
-export([t/0]).
bar(A) -> A.
bar(A,A,A) -> A.
bar(A,A,A,A) -> A.
t() -> bar(0, 0).

The compiler will emit the following message:

typo.erl:6:12: function bar/2 undefined, did you mean bar/1,3,4?
%   6|     t() -> bar(0, 0).
%    |            ^

For compiler errors that can easily be caused by typos, the compiler will try to suggest what the correct variable or function name, could be. For example, given the following module:

-module(typos).
-export([bar/2]).

bar(A0, B0) ->
    A + B.

the compiler will emit the following error messages:

typos.erl:5:5: variable 'A' is unbound, did you mean 'A0'?
%    5|     A + B.
%     |     ^

typos.erl:5:9: variable 'B' is unbound, did you mean 'B0'?
%    5|     A + B.
%     |         ^

Error types that now suggest correct arities: bad_inline, undefined_nif, bad_nowarn_unused_function, bad_nowarn_bif_clash, undefined_function.

Error types that now suggest correct names: bad_inline, undefined_nif, bad_nowarn_unused_function, undefined_on_load, undefined_function, undefined_record, undefined_field, unbound_var.

Using a function with wrong arity has higher precedence than having a typo in the function name. If the compiler can find a defined function with the same name but a different arity, it will not suggest a defined function with a close-enough name, regardless of arity.

OTP-19184
Application(s):
compiler, debugger, stdlib, syntax_tools
Related Id(s):

PR-8926

Comprehensions have been extended with zip generators according to EEP 73.

Example:

1> [A+B || A <- [1,2,3] && B <- [4,5,6]].
[5,7,9]
OTP-19198
Application(s):
erts
Related Id(s):

PR-9269, PR-9519, PR-9590

Functionality making it possible for processes to enable reception of priority messages has been introduced in accordance with EEP 76.

OTP-19314
Application(s):
erts, stdlib
Related Id(s):

GH-8037, PR-8962

The erl -noshell mode has been updated to have two sub modes called raw and cooked, where cooked is the old default behaviour and raw can be used to bypass the line-editing support of the native terminal. Using raw mode it is possible to read keystrokes as they happen without the user having to press Enter. Also, the raw mode does not echo the typed characters to stdout. An example of how to create a tic-tac-toe game using this mechanism is included in the documentation.

OTP-19317
Application(s):
compiler, debugger, stdlib, syntax_tools
Related Id(s):

PR-8625

New strict generators have been added for comprehensions.

The currently existing generators are “relaxed”: they ignore terms in the right-hand side expression that do not match the left-hand side pattern.

The new strict generators fail with exception badmatch if a pattern doesn’t match.

Examples:

Using the current relaxed generator operator <-, any element not matching the pattern {_,_} will be silently discarded:

1> [T || {_,_}=T <- [{ok,1},ok,{error,2}]].
[{ok,1},{error,2}]

If the intention is that all lists processed by a list comprehension must only contain tuples of size two, using the new strict version of the operator ensures that term not matching will cause a crash:

2> [T || {_,_}=T <:- [{ok,1},ok,{error,2}]].
** exception error: no match of right hand side value ok

Using the strict generator operator to mark the intention that all list elements must match the pattern could help finding mistakes quicker if something unpexected is added to the list processed by the generator.

The strict version for bitstring generators is <:=.

OTP-19337
Application(s):
stdlib
Related Id(s):

GH-8099, PR-8100

The join(Binaries, Separator) function that joins a list of binaries has been added to the binary module.

OTP-19364
Application(s):
dialyzer, diameter, edoc, erts, eunit, kernel, mnesia, parsetools, runtime_tools, snmp
Related Id(s):

PR-9079

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19431
POTENTIAL INCOMPATIBILITY
 

Module re has been updated to use PCRE2, which is mostly backward compatible with PCRE.

The most noticeable incompatibilities are

  • The default character encoding is pure ASCII and not Latin1. Unicode support is still available with options unicode and ucp.
  • Options bsr_anycrlf, bsr_unicode and {newline,_} are only set when a regex is compiled and cannot be changed at matching for precompiled regex.
OTP-19452
Application(s):
otp, stdlib
Related Id(s):

PR-9106

It is now possible to use any base for floating point numbers as described in EEP 75: Based Floating Point Literals.

Computers represent floating point numbers in binary, but such numbers are typically printed using base ten, for example 0.314159265e1. To maintain exact bit-level precision when converting numbers to and from text, it is better to use a base that matches the internally used base, such as 16 for a compact but still exact representation, or 2 for visualizing or writing down the exact internal format. One particular case where such exact representations are useful is in code generating tools.

Examples:

> 2#0.111.
0.875
> 16#fefe.fefe#e16.
1.2041849337671418e24
OTP-19477
Application(s):
stdlib
Related Id(s):

PR-9316

There is a new zstd module that does Zstandard compression.

OTP-19502
Application(s):
compiler
Related Id(s):

PR-8695

The compiler’s alias analysis pass is now both faster and less conservative, allowing optimizations of records and binary construction to be applied in more cases.

OTP-19538
Application(s):
stdlib
Related Id(s):

PR-9468

Line numbers used to be reported in the following way:

1> lists:last([]).
** exception error: no function clause matching lists:last([]) (lists.erl, line 389)

Starting from Erlang/OTP 28, line numbers are now reported in the following way:

1> lists:last([]).
** exception error: no function clause matching lists:last([]) (lists.erl:389)
OTP-19553
Application(s):
otp
Related Id(s):

PR-9586, PR-9630, PR-9660, PR-9714

SPDX 2.2 Source Software-Bill-Of-Materials for Erlang/OTP compliant with NTIA minimum requirements.

The SBOM contains a root package. Inside the root package there are multiple SPDX packages. Each SPDX package corresponds to an Erlang/OTP application and the Erlang runtime system (erts). Inside each package, there may be multiple packages, such as vendor dependency packages inside the erts SPDX package.

OTP-19556
Application(s):
stdlib
Related Id(s):

PR-9772

Added functions that produce utf-8 binaries instead of iolists. New functions are: io_lib:bformat/2, io_lib:bformat/3, io_lib:bfwrite/2, io_lib:bfwrite/3, io_lib:bwrite/2 and io_lib:bwrite_string/3.

OTP-19609
Application(s):
compiler, erts, kernel
Related Id(s):

PR-8670, PR-9334, PR-9604

An experimental API for a native debugger has been added. The main components are the following:

  • A new compiler option beam_debug_info for the Erlang compiler. When given, most optimizations are disabled and debug information suitable for the native debugger are added to generated BEAM files.
  • A new +D emulator flag. When given, the VM becomes “debuggable”, which means that when modules that been compiled with the beam_debug_info option are loaded, the code is instrumented so that one can enable and disable breakpoints on executable lines.
  • An experimental erl_debugger module with a new debugging API. Essentially, it allows a single, local, process to be registered as the “debugger” process for the node. This process is the one that will receive messages notifying that a process hit a breakpoint. This way, the front-end implementation of a debugger (such as edb from WhatApp) can be decoupled from OTP.
  • The erl_debugger module also exposes new BIFs to inspect X and Y registers of a suspended process. Together with new code-information BIFs, this let’s a debugger show the values of variables in scope for a suspended process.
OTP-19612
POTENTIAL INCOMPATIBILITY
 

The ancient ASN.1 modules used in public_key has been replaced with more modern versions, but we have strived to keep the documented Erlang API for the public_key application compatible.

OTP-19627
Application(s):
kernel
Related Id(s):

GH-9722, OTP-19576

Removed the default values for SCTP send (sndbuf) and receive (recbuf) buffers.

Potential Incompatibilities #

OTP-19233
Application(s):
stdlib
Related Id(s):

PR-8772

proc_lib:stop/1,3 (and in extension gen_server:stop/3, gen_statem:stop/3 and so on) have been updated to not throw an error if the process to be stopped exits with the same reason as given to proc_lib:stop/3.

OTP-19285
Application(s):
compiler, erts, stdlib
Related Id(s):

PR-8913

The size of an atom in the Erlang source code was limited to 255 bytes in previous releases, meaning that an atom containing only emojis could contain only 63 emojis.

While atoms are still only allowed to contain 255 characters, the number of bytes is no longer limited.

External tools that parse the AtU8 chunk of a BEAM file directly need to be updated. Tools that use beam_lib:chunks(Beam, [atoms]) to read the atom table will continue to work.

OTP-19290
Application(s):
asn1
Related Id(s):

PR-8798

The undec_rest option would be ignored in generated functions for exclusive decode. The option is now respected, meaning that the return value from such functions are now three-tuples instead of a two-tuples.

OTP-19323
Application(s):
compiler, erts, stdlib
Related Id(s):

GH-8967, PR-8988

The literals chunk in BEAM is no longer compressed, resulting in slightly smaller BEAM files when a BEAM file is stripped using beam_lib:strip_files/1.

This is a potential incompatibility for tools that read and interpret the contents of the literal chunk. One way to update such tools to work with the new format is to retrieve the chunk using beam_lib:chunks(Beam, [literals]).

OTP-19355
Application(s):
common_test
Related Id(s):

PR-9045

The abort_if_missing_suites option now defaults to true. If you prefer the old behavior, set abort_if_missing_suites to false in your test runs.

OTP-19420
Application(s):
ssh
Related Id(s):

PR-9277

CBC algorithms are not offered by default. See Configuring algorithms in SSH if you wish to enable them.

OTP-19431
HIGHLIGHT
 

Module re has been updated to use PCRE2, which is mostly backward compatible with PCRE.

The most noticeable incompatibilities are

  • The default character encoding is pure ASCII and not Latin1. Unicode support is still available with options unicode and ucp.
  • Options bsr_anycrlf, bsr_unicode and {newline,_} are only set when a regex is compiled and cannot be changed at matching for precompiled regex.
OTP-19536
Application(s):
erts
Related Id(s):

PR-8670

If a process being suspended using erlang:suspend_process() currently is waiting in a receive ... after expression, the timer for the timeout will now also be suspended until the process is resumed.

OTP-19597
Application(s):
stdlib
Related Id(s):

PR-9680

Change automatic hibernation of static supervisors so that they will hibernate after being idle for 1 second instead of only after starting, dynamic supervisors (simple_one_for_one) will not be hibernated at all. An option to the supervisor is added to make it configurable for the application. This option defaults to 1 second for static supervisors and to infinity for the simple_one_for_one supervisors.

OTP-19612
HIGHLIGHT
 

The ancient ASN.1 modules used in public_key has been replaced with more modern versions, but we have strived to keep the documented Erlang API for the public_key application compatible.

OTP-19615
Application(s):
erts
Related Id(s):

PR-9718

The socket option names for built-in socket options in the module socket has been cleaned up.

Now, for known socket options, it is only the canonical protocol names that are allowed such as ip for the socket option {ip,recvtos}. Previously, due to being a protocol alias; {'IP',recvtos} was also allowed, as was the incorrect {hopopt,recvtos} because the protocol hopopt on Linux has the same protocol number as ip.

So, to reduce confusion, all enumerated protocol names with the same number, are not allowed for the known protocol options, only the canonical name.

OTP-28.0 #

OTP-19452
HIGHLIGHT
 

It is now possible to use any base for floating point numbers as described in EEP 75: Based Floating Point Literals.

Computers represent floating point numbers in binary, but such numbers are typically printed using base ten, for example 0.314159265e1. To maintain exact bit-level precision when converting numbers to and from text, it is better to use a base that matches the internally used base, such as 16 for a compact but still exact representation, or 2 for visualizing or writing down the exact internal format. One particular case where such exact representations are useful is in code generating tools.

Examples:

> 2#0.111.
0.875
> 16#fefe.fefe#e16.
1.2041849337671418e24
OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19492
Related Id(s):

PR-9409

Fixes the sarif generation in the scan code script

OTP-19553
HIGHLIGHT
 

SPDX 2.2 Source Software-Bill-Of-Materials for Erlang/OTP compliant with NTIA minimum requirements.

The SBOM contains a root package. Inside the root package there are multiple SPDX packages. Each SPDX package corresponds to an Erlang/OTP application and the Erlang runtime system (erts). Inside each package, there may be multiple packages, such as vendor dependency packages inside the erts SPDX package.

OTP-19601
Related Id(s):

PR-9717

Fixes wrong relationship order for SPDX packages and mistaken inclusion of erts documentation in the erts test SPDX package.

OTP-19607
Related Id(s):

PR-9758

sbom validates copyrights to be of a specific format, as defined in the LICENSE-HEADERS.md, which will prevent mistakes in copyrights

OTP-19629
Related Id(s):

PR-9791

SBOM produces package url as per the Erlang Ecosystem Foundation guidelines

asn1-5.4 #

OTP-19290
POTENTIAL INCOMPATIBILITY
 

The undec_rest option would be ignored in generated functions for exclusive decode. The option is now respected, meaning that the return value from such functions are now three-tuples instead of a two-tuples.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19612
HIGHLIGHT, POTENTIAL INCOMPATIBILITY
 

The ancient ASN.1 modules used in public_key has been replaced with more modern versions, but we have strived to keep the documented Erlang API for the public_key application compatible.

Full runtime dependencies of asn1-5.4

erts-14.0, kernel-9.0, stdlib-5.0

common_test-1.28 #

OTP-19485
Related Id(s):

PR-8592

Replaced calls to deprecated crypto:start() with application:start(crypto).

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19159
Related Id(s):

PR-7830

The overage reports in HTML can be rendered in dark mode if requested by the user’s browser.

OTP-19355
POTENTIAL INCOMPATIBILITY
 

The abort_if_missing_suites option now defaults to true. If you prefer the old behavior, set abort_if_missing_suites to false in your test runs.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of common_test-1.28

compiler-6.0, crypto-4.5, debugger-4.1, erts-7.0, ftp-1.0, inets-6.0, kernel-8.4, observer-2.1, runtime_tools-1.8.16, sasl-2.5, snmp-5.1.2, ssh-4.0, stdlib-4.0, syntax_tools-1.7, tools-3.2, xmerl-1.3.8

compiler-9.0 #

OTP-19141
Related Id(s):

GH-8558, PR-8600

The compiler will now emit warnings when some map patterns cannot possibly match because a previous clauses matches the same pattern. For example:

mm_1(#{}) -> a;
mm_1(#{b := B}) -> {b,B}.

mm_2(#{a := A}) -> {a,A};
mm_2(#{a := A, b := B}) -> {b,A,B}.

The second clause of these function can never match and the compiler will now emit a warning for both of them.

Note that the compiler is not guaranteed to emit warnings for every possible map pattern that cannot match.

OTP-19285
POTENTIAL INCOMPATIBILITY
 

The size of an atom in the Erlang source code was limited to 255 bytes in previous releases, meaning that an atom containing only emojis could contain only 63 emojis.

While atoms are still only allowed to contain 255 characters, the number of bytes is no longer limited.

External tools that parse the AtU8 chunk of a BEAM file directly need to be updated. Tools that use beam_lib:chunks(Beam, [atoms]) to read the atom table will continue to work.

OTP-19323
POTENTIAL INCOMPATIBILITY
 

The literals chunk in BEAM is no longer compressed, resulting in slightly smaller BEAM files when a BEAM file is stripped using beam_lib:strip_files/1.

This is a potential incompatibility for tools that read and interpret the contents of the literal chunk. One way to update such tools to work with the new format is to retrieve the chunk using beam_lib:chunks(Beam, [atoms])

OTP-19376
Related Id(s):

GH-9113, PR-9121

The final validation step in the compiler will now reject modules containing functions with more than 255 arguments. No impact is expected as the emulator has always refused to load these modules.

OTP-19485
Related Id(s):

PR-8592

Replaced calls to deprecated crypto:start() with application:start(crypto).

OTP-19574
Related Id(s):

PR-9678

Refactor code to not rely on +nowarn_shadow_vars.

OTP-19096
Related Id(s):

PR-8494

The EEP-48 doc chunk embedded into .beam files by the compiler is now compressed and deterministic.

OTP-19115
Related Id(s):

PR-8540

Provided that the map argument for a maps:put/3 call is known to the compiler to be a map, the compiler will replace such calls with the corresponding update using the map syntax.

OTP-19180
HIGHLIGHT
 

For various error types, the compiler now tries to suggest potential fixes by adding “did you mean …?” at the end of error messages.

When a function is used with wrong arity, the compiler will try to suggest a defined function with the same name but a different arity. For example, given the following module:

-module(typos).
-export([t/0]).
bar(A) -> A.
bar(A,A,A) -> A.
bar(A,A,A,A) -> A.
t() -> bar(0, 0).

The compiler will emit the following message:

typo.erl:6:12: function bar/2 undefined, did you mean bar/1,3,4?
%   6|     t() -> bar(0, 0).
%    |            ^

For compiler errors that can easily be caused by typos, the compiler will try to suggest what the correct variable or function name, could be. For example, given the following module:

-module(typos).
-export([bar/2]).

bar(A0, B0) ->
    A + B.

the compiler will emit the following error messages:

typos.erl:5:5: variable 'A' is unbound, did you mean 'A0'?
%    5|     A + B.
%     |     ^

typos.erl:5:9: variable 'B' is unbound, did you mean 'B0'?
%    5|     A + B.
%     |         ^

Error types that now suggest correct arities: bad_inline, undefined_nif, bad_nowarn_unused_function, bad_nowarn_bif_clash, undefined_function.

Error types that now suggest correct names: bad_inline, undefined_nif, bad_nowarn_unused_function, undefined_on_load, undefined_function, undefined_record, undefined_field, unbound_var.

Using a function with wrong arity has higher precedence than having a typo in the function name. If the compiler can find a defined function with the same name but a different arity, it will not suggest a defined function with a close-enough name, regardless of arity.

OTP-19184
HIGHLIGHT
 

Comprehensions have been extended with zip generators according to EEP 73.

Example:

1> [A+B || A <- [1,2,3] && B <- [4,5,6]].
[5,7,9]
OTP-19306
Related Id(s):

PR-8945, PR-8975

Documentation chunks (EEP-48) has been updated to include the following reserved metadata fields: behaviours, group, source_path, and source_annos. The compiler has also been updated to emit this metadata. See the EEP-48 documentation for more details.

OTP-19317
HIGHLIGHT
 

New strict generators have been added for comprehensions.

The currently existing generators are “relaxed”: they ignore terms in the right-hand side expression that do not match the left-hand side pattern.

The new strict generators fail with exception badmatch if a pattern doesn’t match.

Examples:

Using the current relaxed generator operator <-, any element not matching the pattern {_,_} will be silently discarded:

1> [T || {_,_}=T <- [{ok,1},ok,{error,2}]].
[{ok,1},{error,2}]

If the intention is that all lists processed by a list comprehension must only contain tuples of size two, using the new strict version of the operator ensures that term not matching will cause a crash:

2> [T || {_,_}=T <:- [{ok,1},ok,{error,2}]].
** exception error: no match of right hand side value ok

Using the strict generator operator to mark the intention that all list elements must match the pattern could help finding mistakes quicker if something unpexected is added to the list processed by the generator.

The strict version for bitstring generators is <:=.

OTP-19334
Related Id(s):

GH-8985, PR-9020

New options for suppressing behaviour warnings have been added:

  • nowarn_conflicting_behaviours
  • nowarn_undefined_behaviour_func
  • nowarn_undefined_behaviour
  • nowarn_undefined_behaviour_callbacks
  • nowarn_ill_defined_behaviour_callbacks
  • nowarn_ill_defined_optional_callbacks
OTP-19339
Related Id(s):

PR-9042, PR-9122

Some BIFs with side-effects are optimized in try/catch in the same way as guard BIFs in order to gain performance.

The following BIFs that are optimized in this way: binary_to_atom/1, binary_to_atom/2, binary_to_existing_atom/1, list_to_atom/1, and list_to_existing_atom/1.

OTP-19394
Related Id(s):

PR-9192

The compiler now converts known documentation attribute metadata entries from unicode:chardata/0 to unicode:unicode_binary/0.

OTP-19425
Related Id(s):

PR-9154

The warn_deprecated_catch option enables warnings for use of old-style catch expressions on the form catch Expr instead of the modern try ... catch ... end. To prevent new uses of uses of old catches to be added, this compiler option can be enabled on the project level and -compile(nowarn_deprecated_catch). added to individual files that still contain old catches.

OTP-19432
Related Id(s):

PR-9246

Defining a fun in terms of an imported function is not allowed. Before this release, the compiler would not catch this kind of error if the name of the imported function happened to be a BIF. Consider this example:

-module(fun_example).
-export([foo/0, bar/0]).
-import(m, [max/2, not_a_bif/0]).

foo() ->
    fun max/2.

bar() ->
    fun not_a_bif/0.

The compiler in Erlang/OTP 27 would generate the following messages:

fun_example.erl:9:5: function not_a_bif/0 undefined
%    9|     fun not_a_bif/0.
%     |     ^

fun_example.erl:3:2: Warning: import directive overrides auto-imported BIF max/2 --
use "-compile({no_auto_import,[max/2]})." to resolve name clash
%    3| -import(m, [max/2, not_a_bif/0]).
%     |  ^

That is, there would be a (cryptic) error for fun not_a_bif/0, but only a warning for fun max/2.

When compiling with this release, both attempts to create a fun will result in error messages (as well as a warning):

fun_example.erl:6:5: creating a fun from imported name max/2 is not allowed
%    6|     fun max/2.
%     |     ^

fun_example.erl:9:5: creating a fun from imported name not_a_bif/0 is not allowed
%    9|     fun not_a_bif/0.
%     |     ^

fun_example.erl:3:2: Warning: import directive overrides auto-imported BIF max/2 --
use "-compile({no_auto_import,[max/2]})." to resolve name clash
%    3| -import(m, [max/2, not_a_bif/0]).
%     |  ^

Also, attempting to call a local function having the same name as auto-imported BIF would result in an error if the BIF was added to Erlang/OTP before R14, and a warning for newer BIFs. This has been changed to always emit a warning. For example:

-module(bif_example).
-export([bar/1]).

bar(B) ->
    is_boolean(B).

is_boolean(B) ->
        B =:= true orelse B =:= false.

will now result in the following warning instead of an error:

if_example.erl:5:5: Warning: ambiguous call of overridden auto-imported BIF is_boolean/1 --
use erlang:is_boolean/1 or "-compile({no_auto_import,[is_boolean/1]})." to resolve name clash
%    5|     is_boolean(B).
%     |     ^
OTP-19502
HIGHLIGHT
 

The compiler’s alias analysis pass is now both faster and less conservative, allowing optimizations of records and binary construction to be applied in more cases.

OTP-19524
Related Id(s):

PR-9517

BEAM files no longer include a Meta chunk if there are no features used. That slightly decreases the size of BEAM files, and it also ensures that m(Module) and beam_lib:md5(Beam) will match for preloaded modules.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19609
HIGHLIGHT
 

An experimental API for a native debugger has been added. The main components are the following:

  • A new compiler option beam_debug_info for the Erlang compiler. When given, most optimizations are disabled and debug information suitable for the native debugger are added to generated BEAM files.
  • A new +D emulator flag. When given, the VM becomes “debuggable”, which means that when modules that been compiled with the beam_debug_info option are loaded, the code is instrumented so that one can enable and disable breakpoints on executable lines.
  • An experimental erl_debugger module with a new debugging API. Essentially, it allows a single, local, process to be registered as the “debugger” process for the node. This process is the one that will receive messages notifying that a process hit a breakpoint. This way, the front-end implementation of a debugger (such as edb from WhatApp) can be decoupled from OTP.
  • The erl_debugger module also exposes new BIFs to inspect X and Y registers of a suspended process. Together with new code-information BIFs, this let’s a debugger show the values of variables in scope for a suspended process.

Full runtime dependencies of compiler-9.0

crypto-5.1, erts-13.0, kernel-8.4, stdlib-6.0

crypto-5.6 #

OTP-19500
Related Id(s):

PR-9119

Fixed minor potential leak of EVP_MAC when crypto module is unloaded.

OTP-19554

Added copyright and license to crypto_ec_curves.erl

OTP-19155
Related Id(s):

PR-8592

The crypto:start/0, crypto:stop/0, and crypto:enable_fips_mode/1 functions have been deprecated.

OTP-19156
Related Id(s):

PR-8590

Warnings are now logged if module crypto with FIPS-supported OpenSSL is loaded without application crypto being loaded. In this case FIPS will be disabled even if the user had set application parameter fips_mode.

OTP-19426
Related Id(s):

PR-9289

The functionality of crypto:crypto_one_time_aead/6 is now also available in the new functions crypto:crypto_one_time_aead_init/4 and crypto:crypto_one_time_aead/4, which makes it possible to reuse initialization.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19487
Related Id(s):

GH-9366, PR-9410

New key fips_provider_buildinfo in map returned by crypto:info/0. If present, it contains the version of the FIPS provider which may be different than the version of the rest of OpenSSL.

OTP-19510
Related Id(s):

PR-9448

Exported crypto types sha3(), hmac_hash_algorithm() and cmac_cipher_algorithm().

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of crypto-5.6

erts-9.0, kernel-6.0, stdlib-3.9

debugger-6.0 #

OTP-19484
Related Id(s):

GH-7819, PR-9399

Error handling has been improved when modules fail to load.

OTP-19184
HIGHLIGHT
 

Comprehensions have been extended with zip generators according to EEP 73.

Example:

1> [A+B || A <- [1,2,3] && B <- [4,5,6]].
[5,7,9]
OTP-19317
HIGHLIGHT
 

New strict generators have been added for comprehensions.

The currently existing generators are “relaxed”: they ignore terms in the right-hand side expression that do not match the left-hand side pattern.

The new strict generators fail with exception badmatch if a pattern doesn’t match.

Examples:

Using the current relaxed generator operator <-, any element not matching the pattern {_,_} will be silently discarded:

1> [T || {_,_}=T <- [{ok,1},ok,{error,2}]].
[{ok,1},{error,2}]

If the intention is that all lists processed by a list comprehension must only contain tuples of size two, using the new strict version of the operator ensures that term not matching will cause a crash:

2> [T || {_,_}=T <:- [{ok,1},ok,{error,2}]].
** exception error: no match of right hand side value ok

Using the strict generator operator to mark the intention that all list elements must match the pattern could help finding mistakes quicker if something unpexected is added to the list processed by the generator.

The strict version for bitstring generators is <:=.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of debugger-6.0

compiler-8.0, erts-15.0, kernel-10.0, stdlib-7.0, wx-2.0

dialyzer-5.4 #

OTP-19262
Related Id(s):

GH-8822, PR-8885

The -Wno_unknown option will now prevent a warning being printed to standard output when the command line interface is used.

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of dialyzer-5.4

compiler-8.0, erts-12.0, kernel-8.0, stdlib-5.0, syntax_tools-2.0

diameter-2.5 #

OTP-19620
Related Id(s):

PR-9321

With this change diameter will not crash when decoding a DiameterURI without port number.

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19621
Related Id(s):

PR-9786

With this change diameter will not use slave terminology

Full runtime dependencies of diameter-2.5

erts-10.0, kernel-3.2, ssl-9.0, stdlib-5.0

edoc-1.4 #

OTP-19574
Related Id(s):

PR-9678

Refactor code to not rely on +nowarn_shadow_vars.

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of edoc-1.4

erts-11.0, inets-5.10, kernel-7.0, stdlib-4.0, syntax_tools-2.0, xmerl-1.3.7

eldap-1.2.15 #

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of eldap-1.2.15

asn1-3.0, erts-6.0, kernel-3.0, ssl-5.3.4, stdlib-3.4

erl_interface-5.6 #

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19614
Related Id(s):

PR-9775

Update of MD5 implementation from OpenSSL version 3.1.4 to 3.5.

OTP-16607
Related Id(s):

OTP-16608

The ei API for decoding/encoding terms is not fully 64-bit compatible since terms that have a representation on the external term format larger than 2 GB cannot be handled.

erts-16.0 #

OTP-19144
Related Id(s):

PR-8589

ETS tables with more than 2 billion keys are now supported.

OTP-19259
Related Id(s):

PR-8862

The zlib library included in Erlang/OTP has been updated to version 1.3.1.

OTP-19263
Related Id(s):

PR-8943

to_erl no longer clears the screen when attaching to a run_erl session.

OTP-19285
POTENTIAL INCOMPATIBILITY
 

The size of an atom in the Erlang source code was limited to 255 bytes in previous releases, meaning that an atom containing only emojis could contain only 63 emojis.

While atoms are still only allowed to contain 255 characters, the number of bytes is no longer limited.

External tools that parse the AtU8 chunk of a BEAM file directly need to be updated. Tools that use beam_lib:chunks(Beam, [atoms]) to read the atom table will continue to work.

OTP-19295
Related Id(s):

PR-8937

Fixed a bug where erlc would crash if its path contained spaces.

OTP-19313
Related Id(s):

GH-8113, PR-8962

The -noshell mode has been updated to read data lazily from standard input. Before this fix any data would be read greedily which meant that Erlang could consume data not meant for it. It also meant that in order for shell:start_interactive/0 to work on Windows an API that did not support reading of Unicode characters had to be used.

OTP-19323
POTENTIAL INCOMPATIBILITY
 

The literals chunk in BEAM is no longer compressed, resulting in slightly smaller BEAM files when a BEAM file is stripped using beam_lib:strip_files/1.

This is a potential incompatibility for tools that read and interpret the contents of the literal chunk. One way to update such tools to work with the new format is to retrieve the chunk using beam_lib:chunks(Beam, [literals]).

OTP-19453
Related Id(s):

PR-9207

Fixed erlang:localtime_to_universaltime/2 with IsDST set to true and a timezone without daylight saving (for example UTC) to assume that the provided localtime does not have DST. This has always been the behaviour, but glibc versions after 2.37 changed it so that the behavior in Erlang also changed.

OTP-19454
Related Id(s):

PR-9207

Support for the TZ environment variable has been added on Windows. Before this change only the time zone configured in the OS was ever used.

OTP-19488
Related Id(s):

GH-9413, PR-9417

Suppressed various warnings when building the emulator with recent versions of GCC

OTP-19507
Related Id(s):

GH-9438, PR-9478

Fixed a bug in re:run and re:compile where the pattern parameter would be read incorrectly if it was a sub-binary.

OTP-19518
Related Id(s):

GH-9487, PR-9488

Fixed a broken makefile rule that made it so that O2 and -O2 could not be part of the directory path when building Erlang/OTP. Bug has been present since R11B released 2006.

OTP-19532
Related Id(s):

PR-9538

Fixed the index types of modules atomics and counters from integer() to pos_integer(), which is more correct.

OTP-19594
Related Id(s):

GH-9668, PR-9671

Fix erl flags +Q, +P and +t to not allow values greater than 4294975487. Before this fix, the runtime would either truncate the value or crash depending on which value was given.

OTP-19615
POTENTIAL INCOMPATIBILITY
 

The socket option names for built-in socket options in the module socket has been cleaned up.

Now, for known socket options, it is only the canonical protocol names that are allowed such as ip for the socket option {ip,recvtos}. Previously, due to being a protocol alias; {'IP',recvtos} was also allowed, as was the incorrect {hopopt,recvtos} because the protocol hopopt on Linux has the same protocol number as ip.

So, to reduce confusion, all enumerated protocol names with the same number, are not allowed for the known protocol options, only the canonical name.

OTP-19617
Related Id(s):

OTP-19482

On windows, socket:sendv could incorrectly return {ok, integer()} on Windows.

OTP-19198
HIGHLIGHT
 

Functionality making it possible for processes to enable reception of priority messages has been introduced in accordance with EEP 76.

OTP-19271
Related Id(s):

PR-8660

The trace:system/3 function has been added. It has a similar interface as erlang:system_monitor/2 but it also supports trace sessions.

OTP-19278
Related Id(s):

PR-8887, PR-8938

Added support for SIGWINCH, SIGCONT, and SIGINFO signals to os:set_signal/2 where available.

OTP-19314
HIGHLIGHT
 

The erl -noshell mode has been updated to have two sub modes called raw and cooked, where cooked is the old default behaviour and raw can be used to bypass the line-editing support of the native terminal. Using raw mode it is possible to read keystrokes as they happen without the user having to press Enter. Also, the raw mode does not echo the typed characters to stdout. An example of how to create a tic-tac-toe game using this mechanism is included in the documentation.

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19369
Related Id(s):

PR-9129

Two BIFs have been added to the erlang module.

erlang:processes_iterator/0 returns a process iterator that can be used to iterate through the process table.

erlang:process_next/1 takes in a process iterator and returns a 2-tuple, consisting of a process identifier and a new process iterator. When the process iterator runs out of processes in the process table, none will be returned.

Using these BIFs to scan the processes scales better than using erlang:processes/0, at the cost of giving less consistency guarantees. Process identifiers returned from consecutive calls of erlang:process_next/1 may not be a consistent snapshot of all elements existing in the table during any of the calls. A process identifier is only guaranteed to be returned from a call to erlang:processes_next/1 if it was alive before the call to erlang:processes_iterator/0 and was still alive when erlang:processes_next/1 returned none.

OTP-19386

Improved open debug for gen_tcp_socket (connect and listen) and gen_udp_socket (open).

OTP-19431
HIGHLIGHT, POTENTIAL INCOMPATIBILITY
 

Module re has been updated to use PCRE2, which is mostly backward compatible with PCRE.

The most noticeable incompatibilities are

  • The default character encoding is pure ASCII and not Latin1. Unicode support is still available with options unicode and ucp.
  • Options bsr_anycrlf, bsr_unicode and {newline,_} are only set when a regex is compiled and cannot be changed at matching for precompiled regex.
OTP-19450
Related Id(s):

PR-9342

When booting the runtime system on a 32-bit computer with a single core, the boot code will try to minimize the peak memory use by disabling parallel loading of BEAM files.

OTP-19451
Related Id(s):

PR-9344

A socket option {otp,select_read} has been added that enables keeping a socket in the VM select/poll set between calls to recv functions.

This increases throughput by reducing the number of calls to said functions.

OTP-19460
Related Id(s):

GH-9255, PR-9363

erlc will now write compiler warnings and errors to standard error, instead of standard output, in common with other language compilers.

OTP-19465
Related Id(s):

PR-9229

Fixed the Windows build to always include .pdb files for all DLLs and executables to help with debugging.

OTP-19472
Related Id(s):

PR-9388

Improve the naming of the (internal) esock mutex(es). It is now possible to configure (as in autoconf) the use of simple names for the esock mutex(es).

OTP-19473
Related Id(s):

PR-8697, PR-9396

An optimization for appending 0 bits to a binary was removed in patch releases for OTP versions 25, 26, and 27. This optimization has been reintroduced in Erlang/OTP 28.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19479
Related Id(s):

PR-9275

When using enif_select_read (or enif_select with ERL_NIF_SELECT_READ) on systems with kernel polling enabled (that is most Unix systems), file descriptors that are always re-enabled as soon as they trigger are now part of a specialized pollset just as driver_select. This reduces the CPU usage in such scenarios as the erts does not have to re-insert the FD everytime it it triggered. As a result of this optimization socket based reading uses a lot less CPU and achieves a higher throughput.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19481
Related Id(s):

PR-9330

The Windows installer no longer creates the erl.ini file, making installations redistributable.

OTP-19503
Related Id(s):

PR-9406

Added erlang:hibernate/0, which hibernates a process without discarding the stack.

OTP-19509
Related Id(s):

PR-9495

The asmjit library (used by BeamJIT) has been updated to version 029075b84bf0161a761beb63e6eda519a29020db.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19536
POTENTIAL INCOMPATIBILITY
 

If a process being suspended using erlang:suspend_process() currently is waiting in a receive ... after expression, the timer for the timeout will now also be suspended until the process is resumed.

OTP-19539
Related Id(s):

PR-9511

A test module for TLS distribution over socket has been implemented.

OTP-19541
Related Id(s):

PR-9582

Upgrade pcre2 to 10.45

OTP-19551
Related Id(s):

PR-9608

The +R emulator options has been removed. It has had any effect since Erlang/OTP R9.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19576

Increase the default inet-driver buffer size(s). Also introduce kernel parameters for UDP and SCTP to change the sizes when creating (those) sockets.

OTP-19589
Related Id(s):

GH-9500, PR-9639

Add +JPperfdirectory <dir> for specifying which directory Erlang should place perf symbol information files.

OTP-19590
Related Id(s):

PR-9625

Allow multiple static nifs to be part of the same archive. See the NIF documentation for details.

OTP-19591
Related Id(s):

PR-9594

Various improvements reducing lock contention on run queues due to task stealing.

OTP-19603
Related Id(s):

PR-9735

The new implementation has the same behavior as the previous one. The newer compilers already have native support for FP16, so this implementation is only relevant for older compilers. For this reason, the new implementation has not been tested for speed.

OTP-19609
HIGHLIGHT
 

An experimental API for a native debugger has been added. The main components are the following:

  • A new compiler option beam_debug_info for the Erlang compiler. When given, most optimizations are disabled and debug information suitable for the native debugger are added to generated BEAM files.
  • A new +D emulator flag. When given, the VM becomes “debuggable”, which means that when modules that been compiled with the beam_debug_info option are loaded, the code is instrumented so that one can enable and disable breakpoints on executable lines.
  • An experimental erl_debugger module with a new debugging API. Essentially, it allows a single, local, process to be registered as the “debugger” process for the node. This process is the one that will receive messages notifying that a process hit a breakpoint. This way, the front-end implementation of a debugger (such as edb from WhatApp) can be decoupled from OTP.
  • The erl_debugger module also exposes new BIFs to inspect X and Y registers of a suspended process. Together with new code-information BIFs, this let’s a debugger show the values of variables in scope for a suspended process.
OTP-19613
Related Id(s):

PR-9733

Update internal ryu implementation to use latest version. The new version is a little bit faster in some scenarios. ryu is used by float_to_list/1 and similar functions to convert floats to strings.

OTP-19614
Related Id(s):

PR-9775

Update of MD5 implementation from OpenSSL version 3.1.4 to 3.5.

OTP-19618
Related Id(s):

PR-9759, PR-9809

Small optimization in binary_to_term by not allocating an unnecessary large native stack frame.

Full runtime dependencies of erts-16.0

kernel-9.0, sasl-3.3, stdlib-4.1

et-1.7.2 #

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of et-1.7.2

erts-9.0, kernel-5.3, runtime_tools-1.10, stdlib-3.4, wx-1.2

eunit-2.10 #

OTP-19630
Related Id(s):

PR-9794

Fix so that when running tests in parallel and one test is cancelled due to a failing setup, it is report as cancelled. Before this fix the cancellation was ignored.

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of eunit-2.10

erts-9.0, kernel-5.3, stdlib-3.4

ftp-1.2.4 #

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of ftp-1.2.4

erts-7.0, kernel-6.0, runtime_tools-1.15.1, ssl-10.2, stdlib-3.5

inets-9.4 #

OTP-19485
Related Id(s):

PR-8592

Replaced calls to deprecated crypto:start() with application:start(crypto).

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19520
Related Id(s):

PR-9516

Enhanced http client documentation.

OTP-19521
Related Id(s):

PR-9472

Enhance made to mod_esi documentation

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19624
Related Id(s):

PR-9101

Inets Makefiles now create and use dependencies files for .erl files

Full runtime dependencies of inets-9.4

erts-14.0, kernel-9.0, mnesia-4.12, public_key-1.13, runtime_tools-1.8.14, ssl-9.0, stdlib-5.0, stdlib-6.0

jinterface-1.15 #

OTP-19308
Related Id(s):

PR-8960

The .class files of jinterface are now part of the prebuilt archive using Java 8.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

kernel-10.3 #

OTP-19228
Related Id(s):

PR-8820

Fixed an issue where output to the shell would not print the prompt on a new line.

OTP-19296
Related Id(s):

PR-9013

When in shell is in -noshell mode, and in latin1 encoding mode, io requests in latin1 encoding will not be translated to unicode and back to latin1.

OTP-19297
Related Id(s):

PR-9005

Fixed a bug where a composing unicode character would bind to a character not available to the user and deleting that character would cause a crash.

OTP-19313
Related Id(s):

GH-8113, PR-8962

The -noshell mode has been updated to read data lazily from standard input. Before this fix any data would be read greedily which meant that Erlang could consume data not meant for it. It also meant that in order for shell:start_interactive/0 to work on Windows an API that did not support reading of Unicode characters had to be used.

OTP-19414
Related Id(s):

PR-9272

The Erlang shell no longer crashes when a shell prompt ends with an escape sequence.

OTP-19513
Related Id(s):

PR-9433

code:get_doc/1 now works for cover-compiled modules.

OTP-19544
Related Id(s):

PR-9587, OTP-19545

An infinite loop in CNAME loop detection that can cause Out Of Memory has been fixed. This affected CNAME lookup with the internal DNS resolver.

OTP-19555
Related Id(s):

PR-9543

The internal resolver framework has been fixed to wait with the first resolver lookup until the ERL_INETRC environment variable has been applied.

Previously, on some platform(s) (Linux) a first lookup when figuring out the domain name was always placed on the native resolver even if ERL_INETRC was used to disable it.

OTP-19588
Related Id(s):

GH-9436, PR-9595

Fix logger:add_handler(default, ...) to correctly replay events generated during startup when the default logger is set to undefined in logger’s configuration parameters.

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19627
HIGHLIGHT
 

Removed the default values for SCTP send (sndbuf) and receive (recbuf) buffers.

OTP-19194
Related Id(s):

PR-8078

application:load/1 slows down as the number of directories in the code path increases because the call to code:where_is_file/1 for the ‘.app’ file must scan each directory for the app.

code_server maintains a cache of the contents of directories in the path. Re-using that cache when searching for ‘.app’ files in application:load/1 may improve its runtime, especially when loading multiple applications.

OTP-19226
Related Id(s):

PR-8805

The Erlang SSH daemon now uses the same backend to handle multiline functionality as the Erlang shell.

OTP-19278
Related Id(s):

PR-8887, PR-8938

Added support for SIGWINCH, SIGCONT, and SIGINFO signals to os:set_signal/2 where available.

OTP-19287
Related Id(s):

PR-8207

Add net_kernel:allowed/0, it returns a list of nodes that are explicitly allowed to connect to the node by calling net_kernel:allow/1

OTP-19306
Related Id(s):

PR-8945, PR-8975

Documentation chunks (EEP-48) has been updated to include the following reserved metadata fields: behaviours, group, source_path, and source_annos. The compiler has also been updated to emit this metadata. See the EEP-48 documentation for more details.

OTP-19343
Related Id(s):

PR-8642

The erpc:call/3, erpc:call/5, erpc:multicall/3, and erpc:multicall/5 functions now also accept an option map as last argument containing the timeout and always_spawn options. The always_spawn option can be used in order to ensure that the call operation will use a newly spawned process when executing the remote call.

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19386

Improved open debug for gen_tcp_socket (connect and listen) and gen_udp_socket (open).

OTP-19401
Related Id(s):

PR-9116

t:io:standard_error/0 has been updated to write via a NIF API instead of a port. This allows it to access the dirty-scheduler pool and make sure that writes have been written to the OSs stderr when io:format/3 and equivalent return.

OTP-19404
Related Id(s):

PR-9082

Added the option exception_on_failure to os:cmd/2 to make os:cmd/2 raise an exception if the command fails to execute.

OTP-19451
Related Id(s):

PR-9344

A socket option {otp,select_read} has been added that enables keeping a socket in the VM select/poll set between calls to recv functions.

This increases throughput by reducing the number of calls to said functions.

OTP-19522
Related Id(s):

PR-9508

Add a configure chapter to the socket usage guide

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19576

Increase the default inet-driver buffer size(s). Also introduce kernel parameters for UDP and SCTP to change the sizes when creating (those) sockets.

OTP-19609
HIGHLIGHT
 

An experimental API for a native debugger has been added. The main components are the following:

  • A new compiler option beam_debug_info for the Erlang compiler. When given, most optimizations are disabled and debug information suitable for the native debugger are added to generated BEAM files.
  • A new +D emulator flag. When given, the VM becomes “debuggable”, which means that when modules that been compiled with the beam_debug_info option are loaded, the code is instrumented so that one can enable and disable breakpoints on executable lines.
  • An experimental erl_debugger module with a new debugging API. Essentially, it allows a single, local, process to be registered as the “debugger” process for the node. This process is the one that will receive messages notifying that a process hit a breakpoint. This way, the front-end implementation of a debugger (such as edb from WhatApp) can be decoupled from OTP.
  • The erl_debugger module also exposes new BIFs to inspect X and Y registers of a suspended process. Together with new code-information BIFs, this let’s a debugger show the values of variables in scope for a suspended process.

Full runtime dependencies of kernel-10.3

crypto-5.0, erts-15.2.5, sasl-3.0, stdlib-6.0

megaco-4.8 #

OTP-19523

Add missing spec and doc for exported functions.

OTP-19403

Nano seconds are now used for (example) meas result presentation.

Nanoseconds are now used, for example, in meas result presentations.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19570

Add copyright notice to files that still had none.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19598

Tweaked some of the meas examples in order to make them benchmark compatible.

Full runtime dependencies of megaco-4.8

asn1-3.0, debugger-4.0, erts-12.0, et-1.5, kernel-8.0, runtime_tools-1.8.14, stdlib-2.5

mnesia-4.24 #

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of mnesia-4.24

erts-9.0, kernel-5.3, stdlib-5.0

observer-2.18 #

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19528
Related Id(s):

PR-9659

With this change etop from observer application will scroll as top from shell

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of observer-2.18

erts-15.0, et-1.5, kernel-10.0, runtime_tools-2.1, stdlib-5.0, wx-2.3

odbc-2.16 #

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19456
Related Id(s):

PR-9083

Updated odbc configure to enable easier use of iodbc driver.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of odbc-2.16

erts-6.0, kernel-3.0, stdlib-2.0

os_mon-2.11 #

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19207
Related Id(s):

PR-8704

m:disksup will now recognize HAMMER2 volumes.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of os_mon-2.11

erts-14.0, kernel-9.0, sasl-4.2.1, stdlib-5.0

parsetools-2.7 #

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of parsetools-2.7

erts-6.0, kernel-3.0, stdlib-3.4

public_key-1.18 #

OTP-19616
Related Id(s):

GH-9754, PR-9755

Enable public_key to decode legacy certs using md2 hash.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19573
Related Id(s):

GH-9565, PR-9677

Ignore instead of crashing unhandled entries when loading CA-certificates.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19612
HIGHLIGHT, POTENTIAL INCOMPATIBILITY
 

The ancient ASN.1 modules used in public_key has been replaced with more modern versions, but we have strived to keep the documented Erlang API for the public_key application compatible.

Full runtime dependencies of public_key-1.18

asn1-5.0, crypto-5.0, erts-13.0, kernel-8.0, stdlib-4.0

reltool-1.0.2 #

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of reltool-1.0.2

erts-15.0, kernel-9.0, sasl-4.2.1, stdlib-5.0, tools-2.6.14, wx-2.3

runtime_tools-2.2 #

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19584
Related Id(s):

PR-9711

With this change observer will use cheaper iterators to avoid locking when not necessary.

Full runtime dependencies of runtime_tools-2.2

erts-16.0, kernel-10.0, mnesia-4.12, stdlib-6.0

sasl-4.3 #

OTP-19279
Related Id(s):

GH-8842, PR-8894

Fixed the documentation for the ExtraFiles option to systools:make_tar/2.

OTP-19398
Related Id(s):

PR-8973

.appup files are now included in releases in order to make it possible to create upgrade packages from an installed release.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of sasl-4.3

erts-15.0, kernel-6.0, stdlib-4.0, tools-2.6.14

snmp-5.19 #

OTP-19364
HIGHLIGHT
 

EEP-69: Nominal Types has been implemented. As a side effect, nominal types can encode opaque types. We changed all opaque-handling logic and improved opaque warnings in Dialyzer.

All existing Erlang type systems are structural: two types are seen as equivalent if their structures are the same. Type comparisons are based on the structures of the types, not on how the user explicitly defines them. For example, in the following example, meter() and foot() are equivalent. The two types can be used interchangeably. Neither of them differ from the basic type integer().

-type meter() :: integer().
-type foot() :: integer().

Nominal typing is an alternative type system, where two types are equivalent if and only if they are declared with the same type name. The EEP proposes one new syntax -nominal for declaring nominal types. Under nominal typing, meter() and foot() are no longer compatible. Whenever a function expects type meter(), passing in type foot() would result in a Dialyzer error.

-nominal meter() :: integer().
-nominal foot() :: integer().

More nominal type-checking rules can be found in the EEP. It is worth noting that most work for adding nominal types and type-checking is in erl_types.erl. The rest are changes that removed the previous opaque type-checking, and added an improved version of it using nominal type-checking with reworked warnings.

Backwards compatibility for opaque type-checking is not preserved by this PR. Previous opaque warnings can appear with slightly different wordings. A new kind of opaque warning opaque_union is added, together with a Dialyzer option no_opaque_union to turn this kind of warnings off.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19572

Add copyright notice to files that still had none.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of snmp-5.19

crypto-4.6, erts-12.0, kernel-8.0, mnesia-4.12, runtime_tools-1.8.14, stdlib-5.0

ssh-5.3 #

OTP-19324
Related Id(s):

GH-8223, PR-8968

The implementation of the ssh server-side supervision tree has been improved.

OTP-19566
Related Id(s):

PR-9571

SSH daemon accepts fun as tcpip_tunnel_in option. This provides more control over TCP connection tunnel handle by server.

OTP-19226
Related Id(s):

PR-8805

The Erlang SSH daemon now uses the same backend to handle multiline functionality as the Erlang shell.

OTP-19420
POTENTIAL INCOMPATIBILITY
 

CBC algorithms are not offered by default. See Configuring algorithms in SSH if you wish to enable them.

OTP-19535
Related Id(s):

PR-9149

Daemon can be configured (bannerfun option) to send banner message at the beginning of user authentication.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19586
Related Id(s):

PR-9214

For interoperability reasons, SSH ignore message with no length specified is treated as message with zero length specified - it will not cause decode error.

OTP-19596
Related Id(s):

PR-9298

Documentation improvements.

Full runtime dependencies of ssh-5.3

crypto-5.0, erts-14.0, kernel-10.3, public_key-1.6.1, runtime_tools-1.15.1, stdlib-5.0, stdlib-6.0

ssl-11.3 #

OTP-19367
Related Id(s):

PR-9019

Refactoring, minor optimizations and improved log printouts.

OTP-19406
Related Id(s):

PR-9231

supervisor:which_child/2 is now used to make start-up code for TLS-connections simpler and more straight forward, and to increase stability and maintainability of the ssl application.

OTP-19430
Related Id(s):

PR-9305

The data handling for tls-v1.3 has been optimized.

OTP-19463
Related Id(s):

PR-9398

Added experimental socket support.

OTP-19531
Related Id(s):

PR-9563

Improve code health by removing dead code.

OTP-19539
Related Id(s):

PR-9511

A test module for TLS distribution over socket has been implemented.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of ssl-11.3

crypto-5.6, erts-16.0, inets-5.10.7, kernel-10.3, public_key-1.16.4, runtime_tools-1.15.1, stdlib-7.0

stdlib-7.0 #

OTP-19161
Related Id(s):

PR-8573

Shell help now orders the commands in alphabetical order.

OTP-19233
POTENTIAL INCOMPATIBILITY
 

proc_lib:stop/1,3 (and in extension gen_server:stop/3, gen_statem:stop/3 and so on) have been updated to not throw an error if the process to be stopped exits with the same reason as given to proc_lib:stop/3.

OTP-19285
POTENTIAL INCOMPATIBILITY
 

The size of an atom in the Erlang source code was limited to 255 bytes in previous releases, meaning that an atom containing only emojis could contain only 63 emojis.

While atoms are still only allowed to contain 255 characters, the number of bytes is no longer limited.

External tools that parse the AtU8 chunk of a BEAM file directly need to be updated. Tools that use beam_lib:chunks(Beam, [atoms]) to read the atom table will continue to work.

OTP-19303
Related Id(s):

PR-8932

argparse:help/1 now accepts unicode:chardata/0.

OTP-19323
POTENTIAL INCOMPATIBILITY
 

The literals chunk in BEAM is no longer compressed, resulting in slightly smaller BEAM files when a BEAM file is stripped using beam_lib:strip_files/1.

This is a potential incompatibility for tools that read and interpret the contents of the literal chunk. One way to update such tools to work with the new format is to retrieve the chunk using beam_lib:chunks(Beam, [atoms])

OTP-19393
Related Id(s):

PR-9171

The previous digraph_utils:preorder/1 and digraph_utils:postorder/1 did not start the traversal from root nodes. This fix makes both traversals only start or restart from a root node in one of the components, or an arbitrary node if no root node can be visited.

OTP-19413
Related Id(s):

PR-9271

Auto-completion in the shell is now significantly faster for function parameters that uses complex custom types.

OTP-19421
Related Id(s):

GH-9173, PR-9276

Stringfying a non-latin1 atom will now produce a readable string instead of encoding each character using \x{...} escape sequences. Example:

-define(S(T), ??T).

atom() ->
    ?S('атом').

The atom/0 function now returns "'атом'" instead of "'\\x{430}\\x{442}\\x{43E}\\x{43C}'".

OTP-19422
Related Id(s):

PR-9253

A few minor issues were corrected in syntax_tools, as well in the erl_anno module.

OTP-19427
Related Id(s):

PR-9232, PR-9446

m:dets could print error messages to standard output when repairing DETS files. This has been changed to send the messages to logger.

ets:fun2ms would print an error message to standard output as well as returning an error tuple. The printing of the message has been removed.

OTP-19441
Related Id(s):

GH-9279, PR-9280

The functions for converting to and from the RFC1339 date and time format would not properly handle fractional seconds for negative times.

OTP-19485
Related Id(s):

PR-8592

Replaced calls to deprecated crypto:start() with application:start(crypto).

OTP-19511
Related Id(s):

GH-9470

Fixed a bug when calling shell completion on a reserved word followed by a ( would crash the shell.

OTP-19514
Related Id(s):

PR-9504

Corrected the spec of ets:update_element/4.

OTP-19515
Related Id(s):

PR-9514

Corrected the spec for ets:info/1.

OTP-19533
Related Id(s):

GH-9557

Fixed crash when defining records with a string field in the shell

OTP-19540
Related Id(s):

PR-9579

Details in the hibernation implementation and time-out handling has been improved for gen_statem. In particular to avoid selective receive when cancelling a time-out.

OTP-19583
Related Id(s):

PR-9654

Fixed a bug when getting help on a module compiled without debug_info.

OTP-19593
Related Id(s):

GH-9536, PR-9537

Fix zip extraction to wrap invalid DOS timestamps to their correct value instead of returning the actual value. Before this fix the timestamp returned could have a second greater than 59. The bug has been present since Erlang/OTP 27.1.

OTP-19604
Related Id(s):

PR-9574

Enhance specs of timeout for improving documentation and dialyzer analysis.

OTP-19125
Related Id(s):

PR-8556

Singleton type variables in an union type do not make sense from Dialyzer’s point of view. The following example is ill-typed:

-spec run_test(Opts) -> term()
      when Opts :: {join_specs, Bool} | {test, Bool}.

This used to be reported as a warning. In OTP-28, this is an error

OTP-19127
Related Id(s):

PR-8429

By default, sets created by the sets module will now be represented as maps.

OTP-19180
HIGHLIGHT
 

For various error types, the compiler now tries to suggest potential fixes by adding “did you mean …?” at the end of error messages.

When a function is used with wrong arity, the compiler will try to suggest a defined function with the same name but a different arity. For example, given the following module:

-module(typos).
-export([t/0]).
bar(A) -> A.
bar(A,A,A) -> A.
bar(A,A,A,A) -> A.
t() -> bar(0, 0).

The compiler will emit the following message:

typo.erl:6:12: function bar/2 undefined, did you mean bar/1,3,4?
%   6|     t() -> bar(0, 0).
%    |            ^

For compiler errors that can easily be caused by typos, the compiler will try to suggest what the correct variable or function name, could be. For example, given the following module:

-module(typos).
-export([bar/2]).

bar(A0, B0) ->
    A + B.

the compiler will emit the following error messages:

typos.erl:5:5: variable 'A' is unbound, did you mean 'A0'?
%    5|     A + B.
%     |     ^

typos.erl:5:9: variable 'B' is unbound, did you mean 'B0'?
%    5|     A + B.
%     |         ^

Error types that now suggest correct arities: bad_inline, undefined_nif, bad_nowarn_unused_function, bad_nowarn_bif_clash, undefined_function.

Error types that now suggest correct names: bad_inline, undefined_nif, bad_nowarn_unused_function, undefined_on_load, undefined_function, undefined_record, undefined_field, unbound_var.

Using a function with wrong arity has higher precedence than having a typo in the function name. If the compiler can find a defined function with the same name but a different arity, it will not suggest a defined function with a close-enough name, regardless of arity.

OTP-19184
HIGHLIGHT
 

Comprehensions have been extended with zip generators according to EEP 73.

Example:

1> [A+B || A <- [1,2,3] && B <- [4,5,6]].
[5,7,9]
OTP-19204
Related Id(s):

PR-8261

Before restarting a child, a supervisor must check if the restart limit is reached. This adds a penalty to the overall restart time, which should be kept low. The algorithm has been optimized from 2*O(n) to O(n) behavior.

OTP-19224
Related Id(s):

PR-8651

Added the possibility to configure shell docs column width through the stdlib parameter shell_docs_columns.

OTP-19230
Related Id(s):

PR-8792

The io:setopts/2 function now accepts the line_history option for more explicit handling of when to save shell history.

OTP-19231
Related Id(s):

PR-8793

The shell now prints a help message explaining how to interrupt a running command when stuck executing a command for longer than 5 seconds.

OTP-19250
Related Id(s):

PR-8812

Binaries can now be used as input to calendar:rfc3339_to_system_time/2, and produced as output of calendar:system_time_to_rfc3339/2.

OTP-19314
HIGHLIGHT
 

The erl -noshell mode has been updated to have two sub modes called raw and cooked, where cooked is the old default behaviour and raw can be used to bypass the line-editing support of the native terminal. Using raw mode it is possible to read keystrokes as they happen without the user having to press Enter. Also, the raw mode does not echo the typed characters to stdout. An example of how to create a tic-tac-toe game using this mechanism is included in the documentation.

OTP-19315
Related Id(s):

PR-8962, PR-9006

Added io:get_password/0 that can read passwords from stdin when in “raw” -noshell mode.

OTP-19317
HIGHLIGHT
 

New strict generators have been added for comprehensions.

The currently existing generators are “relaxed”: they ignore terms in the right-hand side expression that do not match the left-hand side pattern.

The new strict generators fail with exception badmatch if a pattern doesn’t match.

Examples:

Using the current relaxed generator operator <-, any element not matching the pattern {_,_} will be silently discarded:

1> [T || {_,_}=T <- [{ok,1},ok,{error,2}]].
[{ok,1},{error,2}]

If the intention is that all lists processed by a list comprehension must only contain tuples of size two, using the new strict version of the operator ensures that term not matching will cause a crash:

2> [T || {_,_}=T <:- [{ok,1},ok,{error,2}]].
** exception error: no match of right hand side value ok

Using the strict generator operator to mark the intention that all list elements must match the pattern could help finding mistakes quicker if something unpexected is added to the list processed by the generator.

The strict version for bitstring generators is <:=.

OTP-19334
Related Id(s):

GH-8985, PR-9020

New options for suppressing behaviour warnings have been added:

  • nowarn_conflicting_behaviours
  • nowarn_undefined_behaviour_func
  • nowarn_undefined_behaviour
  • nowarn_undefined_behaviour_callbacks
  • nowarn_ill_defined_behaviour_callbacks
  • nowarn_ill_defined_optional_callbacks
OTP-19337
HIGHLIGHT
 

The join(Binaries, Separator) function that joins a list of binaries has been added to the binary module.

OTP-19345
Related Id(s):

PR-8976

The supervisor:which_child/2 function has been added to facilitate getting the pid of a sibling process; that is a process under same supervisor as the process that calls to call the new function.

OTP-19354
Related Id(s):

PR-8966

The function erl_anno:set_end_location/2 for setting the end location of a token has been added.

OTP-19371
Related Id(s):

GH-9092, PR-9095

Added a warning for calling non-exported functions with the remote function call syntax from the same module, and likewise for the remote fun syntax.

OTP-19425
Related Id(s):

PR-9154

The warn_deprecated_catch option enables warnings for use of old-style catch expressions on the form catch Expr instead of the modern try ... catch ... end. To prevent new uses of uses of old catches to be added, this compiler option can be enabled on the project level and -compile(nowarn_deprecated_catch). added to individual files that still contain old catches.

OTP-19431
HIGHLIGHT, POTENTIAL INCOMPATIBILITY
 

Module re has been updated to use PCRE2, which is mostly backward compatible with PCRE.

The most noticeable incompatibilities are

  • The default character encoding is pure ASCII and not Latin1. Unicode support is still available with options unicode and ucp.
  • Options bsr_anycrlf, bsr_unicode and {newline,_} are only set when a regex is compiled and cannot be changed at matching for precompiled regex.
OTP-19432
Related Id(s):

PR-9246

Defining a fun in terms of an imported function is not allowed. Before this release, the compiler would not catch this kind of error if the name of the imported function happened to be a BIF. Consider this example:

-module(fun_example).
-export([foo/0, bar/0]).
-import(m, [max/2, not_a_bif/0]).

foo() ->
    fun max/2.

bar() ->
    fun not_a_bif/0.

The compiler in Erlang/OTP 27 would generate the following messages:

fun_example.erl:9:5: function not_a_bif/0 undefined
%    9|     fun not_a_bif/0.
%     |     ^

fun_example.erl:3:2: Warning: import directive overrides auto-imported BIF max/2 --
use "-compile({no_auto_import,[max/2]})." to resolve name clash
%    3| -import(m, [max/2, not_a_bif/0]).
%     |  ^

That is, there would be a (cryptic) error for fun not_a_bif/0, but only a warning for fun max/2.

When compiling with this release, both attempts to create a fun will result in error messages (as well as a warning):

fun_example.erl:6:5: creating a fun from imported name max/2 is not allowed
%    6|     fun max/2.
%     |     ^

fun_example.erl:9:5: creating a fun from imported name not_a_bif/0 is not allowed
%    9|     fun not_a_bif/0.
%     |     ^

fun_example.erl:3:2: Warning: import directive overrides auto-imported BIF max/2 --
use "-compile({no_auto_import,[max/2]})." to resolve name clash
%    3| -import(m, [max/2, not_a_bif/0]).
%     |  ^

Also, attempting to call a local function having the same name as auto-imported BIF would result in an error if the BIF was added to Erlang/OTP before R14, and a warning for newer BIFs. This has been changed to always emit a warning. For example:

-module(bif_example).
-export([bar/1]).

bar(B) ->
    is_boolean(B).

is_boolean(B) ->
        B =:= true orelse B =:= false.

will now result in the following warning instead of an error:

if_example.erl:5:5: Warning: ambiguous call of overridden auto-imported BIF is_boolean/1 --
use erlang:is_boolean/1 or "-compile({no_auto_import,[is_boolean/1]})." to resolve name clash
%    5|     is_boolean(B).
%     |     ^
OTP-19452
HIGHLIGHT
 

It is now possible to use any base for floating point numbers as described in EEP 75: Based Floating Point Literals.

Computers represent floating point numbers in binary, but such numbers are typically printed using base ten, for example 0.314159265e1. To maintain exact bit-level precision when converting numbers to and from text, it is better to use a base that matches the internally used base, such as 16 for a compact but still exact representation, or 2 for visualizing or writing down the exact internal format. One particular case where such exact representations are useful is in code generating tools.

Examples:

> 2#0.111.
0.875
> 16#fefe.fefe#e16.
1.2041849337671418e24
OTP-19474
Related Id(s):

PR-9333

The callback function handle_continue/2 in gen_server callback modules is now cached like the others, thanks to code cleanup and optimization of the internal behaviour loop.

This should only improve performance, not affect functionality.

OTP-19476
Related Id(s):

PR-9251

Encoding done by the json module has been optimized.

OTP-19477
HIGHLIGHT
 

There is a new zstd module that does Zstandard compression.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19483
Related Id(s):

PR-9408 ```

Functions of a module can now be grouped in the shell code completion by using the group key in the -doc attribute e.g. ``` -doc(#{group=>«“Public API”»). fetch()->…

```.

Functions, callbacks and types in the module reference documentation of OTP is now grouped using this feature.

OTP-19505
Related Id(s):

PR-9445

Added calendar:universal_time_to_system_time/1,2 and calendar:local_time_to_system_time/1,2

OTP-19508
Related Id(s):

PR-9484

Improve error messages for json:decode/1.

OTP-19512
Related Id(s):

PR-7970

ETS heir can be set without getting an ETS-TRANSFER message. Useful when the heir is a supervisor process that cannot handle custom messages.

OTP-19516
Related Id(s):

PR-9141, PR-9518

Added support for the Unicode 16 standard.

OTP-19526
Related Id(s):

PR-9515

When documenting a function or type that needs to deal with durations, usually we can document it as “time in milliseconds”. Since the timer family of functions (hms, hours, seconds, …) all return time in milliseconds, it is useful to be able to use this type in type specifications.

OTP-19537
Related Id(s):

PR-9287, PR-9615, PR-9621

A new event time-out has been implemented in gen_server, that behaves more like the one in gen_statem.

See the type gen_server:action/0 for {timeout|hibernate,...}, and also related functions.

OTP-19538
HIGHLIGHT
 

Line numbers used to be reported in the following way:

1> lists:last([]).
** exception error: no function clause matching lists:last([]) (lists.erl, line 389)

Starting from Erlang/OTP 28, line numbers are now reported in the following way:

1> lists:last([]).
** exception error: no function clause matching lists:last([]) (lists.erl:389)
OTP-19541
Related Id(s):

PR-9582

Upgrade pcre2 to 10.45

OTP-19556
HIGHLIGHT
 

Added functions that produce utf-8 binaries instead of iolists. New functions are: io_lib:bformat/2, io_lib:bformat/3, io_lib:bfwrite/2, io_lib:bfwrite/3, io_lib:bwrite/2 and io_lib:bwrite_string/3.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

OTP-19578
Related Id(s):

PR-9705

A list of PCRE2 incompatibilities is documented in a user’s guide for stdlib.

OTP-19597
POTENTIAL INCOMPATIBILITY
 

Change automatic hibernation of static supervisors so that they will hibernate after being idle for 1 second instead of only after starting, dynamic supervisors (simple_one_for_one) will not be hibernated at all. An option to the supervisor is added to make it configurable for the application. This option defaults to 1 second for static supervisors and to infinity for the simple_one_for_one supervisors.

Full runtime dependencies of stdlib-7.0

compiler-5.0, crypto-4.5, erts-16.0, kernel-10.0, sasl-3.0, syntax_tools-3.2.1

syntax_tools-4.0 #

OTP-19422
Related Id(s):

PR-9253

A few minor issues were corrected in syntax_tools, as well in the erl_anno module.

OTP-19184
HIGHLIGHT
 

Comprehensions have been extended with zip generators according to EEP 73.

Example:

1> [A+B || A <- [1,2,3] && B <- [4,5,6]].
[5,7,9]
OTP-19317
HIGHLIGHT
 

New strict generators have been added for comprehensions.

The currently existing generators are “relaxed”: they ignore terms in the right-hand side expression that do not match the left-hand side pattern.

The new strict generators fail with exception badmatch if a pattern doesn’t match.

Examples:

Using the current relaxed generator operator <-, any element not matching the pattern {_,_} will be silently discarded:

1> [T || {_,_}=T <- [{ok,1},ok,{error,2}]].
[{ok,1},{error,2}]

If the intention is that all lists processed by a list comprehension must only contain tuples of size two, using the new strict version of the operator ensures that term not matching will cause a crash:

2> [T || {_,_}=T <:- [{ok,1},ok,{error,2}]].
** exception error: no match of right hand side value ok

Using the strict generator operator to mark the intention that all list elements must match the pattern could help finding mistakes quicker if something unpexected is added to the list processed by the generator.

The strict version for bitstring generators is <:=.

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of syntax_tools-4.0

compiler-9.0, erts-16.0, kernel-10.3, stdlib-7.0

tftp-1.2.3 #

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of tftp-1.2.3

erts-6.0, kernel-6.0, stdlib-5.0

tools-4.1.2 #

OTP-19135
Related Id(s):

GH-8483, PR-8547

A crash has been eliminated in tprof:collect/0 when unloading a module while collecting traces.

OTP-19396
Related Id(s):

PR-9186

Improved the indent-region Emacs command, which could indent badly when inside multiline string.

OTP-19419
Related Id(s):

PR-9219

eprof:start_profiling/3 can now return information about which process it failed to trace.

OTP-19517
Related Id(s):

PR-9124

Fixed a race condition when processes cause the Cover server to be started at the same time.

OTP-19580
Related Id(s):

PR-9648

Fix bug in tprof where the session name could not be set.

OTP-19628
Related Id(s):

PR-9787

Add tprof to the .app file.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of tools-4.1.2

compiler-8.5, erts-15.0, erts-15.0, kernel-10.0, runtime_tools-2.1, stdlib-6.0

wx-2.5 #

OTP-19478
Related Id(s):

PR-9376, PR-9402, PR-9819

Fixed licenses in files and added ORT curations to the following apps: otp, eldap, erl_interface, eunit, parsetools, stdlib, syntax_tools, and ERTS.

OTP-19480
Related Id(s):

PR-8734

Added support for compiling Erlang/OTP for Windows on ARM64.

OTP-19519
Related Id(s):

PR-9441

When compiling C/C++ code on Unix systems, the compiler hardening flags suggested by the Open Source Security Foundation are now enabled by default. To disable them, pass --disable-security-hardening-flags to configure.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of wx-2.5

erts-12.0, kernel-8.0, stdlib-5.0

xmerl-2.1.4 #

OTP-19534
Related Id(s):

PR-9327

With this change all public functions in xmerl have specs.

OTP-19575
Related Id(s):

PR-9670

The license and copyright header has changed format to include an SPDX-License-Identifier. At the same time, most files have been updated to follow a uniform standard for license headers.

Full runtime dependencies of xmerl-2.1.4

erts-6.0, kernel-8.4, stdlib-2.5

Thanks To #

Adam Wight, Aleksander Lisiecki, Alexandre Rodrigues, Anders Ågren Thuné, Andrea Leopardi, Ariel Otilibili, Benedikt Reinartz, Benjamin Philip, Brujo Benavides, Chris Freeze, Christophe De Troyer, Cocoa, Dairon Medina Caro, Daniel Gorin, Daniel Kozmacs, Dániel Szoboszlay, dependabot[bot], Dmitri Vereshchagin, Dominic Letz, Douglas Vought, Egor Ignatov, Eksperimental, Frank Hunleth, Freddie Lamble, Fredrik Frantzen, Frej Drejhammar, Gary Rennie, Hichem Fantar, Ilya Klyuchnikov, iri, Isabell H, Jan Uhlig, Jean-Louis Huynen, Jean-Sébastien Pédron, João Henrique Ferreira de Freitas, Johannes Christ, Jonas Bernoulli, Jonatan Kłosko, José Valim, Juan Barrios, Julian Doherty, Keyhan Jannat Khah ☕, Kirill A. Korinsky, lucioleKi, Lukasz Samson, Maria Scott, Mario Idival, Mario Uher, Marko Mindek, Martin Davidsson, Matwey V. Kornilov, Maxim Fedorov, Michael Davis, Michael Neumann, Nelson Vides, Nicholas Moen, Onno Vos, Paul Guyot, Philip Munksgaard, preciz, Richard Carlsson, Roberto Aloi, Robin Morisset, Roeland van Batenburg, ruslandoga, Ryan Kirkman, S0AndS0, sabiwara, Sam Weaver, Sergei Shuvatov, siiky, Simon Cornish, Siri Hansen, Stavros Aronis, Stefan Grundmann, Steffen Deusch, Tobias Pfeiffer, Tomer, Vadim Yanitskiy, Vance Shipley, William Fank Thomé, williamthome, William Yang, Wojtek Mach, Wojtek Surowka, yagogarea, Yoshiyuki Kurauchi, Zero King