OCaml Changelog

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Read the latest releases and updates from the OCaml ecosystem.

In the last two weeks, two significant bugs have been discovered in the release candidate for OCaml 5.1.0 (one affecting the type system, another in the runtime).

Those bugs are now fixed and we are publishing a second release candidate to check that everything is in order before the release in the upcoming week.

If you find any bugs, please report them on OCaml's issue tracker.

The full changelog for OCaml 5.1.0 is available on GitHub. A short summary of the two fixed bugs in this release candidate is also available below.


Installation Instructions

The base compiler can be installed as an opam switch with the following commands on opam 2.1 and later:

opam update
opam switch create 5.1.0~rc2

The source code for the release candidate is also directly available on:

Fine-Tuned Compiler Configuration

If you want to tweak the configuration of the compiler, you can switch to the option variant with:

opam update
opam switch create <switch_name> ocaml-variants.5.1.0~rc2+options <option_list>

where <option_list> is a comma-separated list of ocaml-option-* packages. For instance, for a flambda and no-flat-float-array switch:

opam switch create 5.1.0~rc2+flambda+nffa ocaml-variants.5.1.0~rc2+options ocaml-option-flambda ocaml-option-no-flat-float-array

All available options can be listed with opam search ocaml-option.

See full changelog

Last Minute Bug Fixes

Type System:

  • (breaking change) #6941, #11187, +#12483: prohibit using classes through recursive modules inheriting or including a class belonging to a mutually-recursive module would previous behave incorrectly, and now results in a clean error. (Leo White, review by Gabriel Scherer and Florian Angeletti)

Runtime

  • #12481, #12505: Fix incorrect initialization of array expressions [|e1;...;eN|] when N is large enough to require major heap allocation. (Xavier Leroy, report by Andrey Popp, analysis by KC Sivaramakrishnan and Vincent Laviron, review by Gabriel Scherer)

We're thrilled to announce the release of Merlin 4.10, which comes with many bug fixes and improvements.

One of the standout features of this release is the significantly enhanced support for binding operators like let+ and and+. You'll find that the results from type-enclosing on expressions that contain let bindings are now more precise.

See full changelog
  • merlin binary
    • Constrain socket path buffer size to avoid build warnings (#1631)
    • Handle concurrent server start (#1622)
    • Omit module prefixes for constructors and record fields in the construct command (#1618). Prefixes are still produced when warning 42 (disambiguated name) is active.
    • Correctly invalidate PPX cache when pipeline ran partially (#1650, fixes #1647)
    • Prevent short-path from looping in some cases related to recursive type definitions (#1645)
    • Support parsing negative numbers in sexps (#1655)
    • Fix construct not working with inline records (#1658)
    • Improve behavior of type-enclosing on let/and operators (#1653)
    • Fix occurrences of extension constructors (#1662)
    • Improve node selection when ghosts are present (#1664, fixes #1660)
  • editor modes
    • emacs: call merlin-client-logger with "interrupted" if the merlin binary itself is interrupted, not just the parsing of the result (#1626).
    • emacs: merlin-construct, with a prefix argument, now includes local values in the completion options. Alternatively, this behavior can be enabled permanently by customizing merlin-construct-with-local-values (#1644)
    • emacs: add support for opam-switch-mode (#1654, fixes #1591). See https://github.com/ProofGeneral/opam-switch-mode

Odoc 2.2.1

As OCaml 5.1 is on the horizon, we're excited to announce the release of odoc 2.2.1. This latest version brings compatibility with the upcoming OCaml 5.1 release.

See full changelog

Additions

  • OCaml 5.1.0 compatibility (@Octachron, #956)

The release of OCaml 5.1.0 is imminent. As a final step, we are publishing a release candidate to check that everything is in order before the release in the upcoming week(s).

If you find any bugs, please report them on OCaml's issue tracker.

Compared to the beta release, this release contains one safe runtime fix and two configuration tweaks.

The full change log for OCaml 5.1.0 is available on GitHub A short summary of the changes since the beta release is also available below.


Installation Instructions

The base compiler can be installed as an opam switch with the following commands on opam 2.1 and later:

opam update
opam switch create 5.1.0~rc1

The source code for the release candidate is also directly available on:

Fine-Tuned Compiler Configuration

If you want to tweak the configuration of the compiler, you can switch to the option variant with:

opam update
opam switch create <switch_name> ocaml-variants.5.1.0~rc1+options <option_list>

where <option_list> is a comma-separated list of ocaml-option-* packages. For instance, for a flambda and no-flat-float-array switch:

opam switch create 5.1.0~rc1+flambda+nffa ocaml-variants.5.1.0~rc1+options ocaml-option-flambda ocaml-option-no-flat-float-array

All available options can be listed with opam search ocaml-option.

See full changelog

Changes Since the Beta

Bug Fix

  • #12445: missing GC root registrations in runtime/io.c (Gabriel Scherer, review by Xavier Leroy and Jeremy Yallop)

Configuration Fix (openBSD)

  • #12372: Pass option -no-execute-only to the linker for OpenBSD >= 7.3 so that code sections remain readable, as needed for closure marshaling. (Xavier Leroy and Anil Madhavapeddy, review by Anil Madhavapeddy and Sébastien Hinderer)

Tool Fix (ocamlmktop)

  • #11745, #12358: Debugger and toplevels: embed printer types rather than reading their representations from topdirs.cmi at runtime. This change also removes the ocamlmktop initialisation module introduced in #11382 which was no longer useful. This change breaks toplevel scripts relying on the visibility of Topdirs in the initial toplevel environment without loading topfind. Since the opam default .ocamlinit file loads topfind, it is expected that only scripts run with ocaml -noinit are affected. For those scripts, accessing Topdirs now requires the compiler-libs directory to be added to the toplevel search path with
      #directory "+compiler-libs";;
    

as was already the case for the other modules in the toplevel interface library. (Sébastien Hinderer, review by Florian Angeletti, Nicolás Ojeda Bär, and Gabriel Scherer)

Documentation Changes

  • #12201: in the tutorial on modules, replace priority queue example by a simpler example based on FIFO queues. (Xavier Leroy, review by Anil Madhavapeddy and Nicolás Ojeda Bär).

  • #12352: Fix a typo in the documentation of Arg.write_arg (Christophe Raffalli, review by Florian Angeletti)

Dune 3.9.3

The fix to sendfile in 3.9.2 was not quite enough so here is the last part of the fix. It brings compatibility with filesystems where sendfile is not available, in particular when ecryptfs is used.

See full changelog

Fixes

  • Fix flushing when using sendfile fallback (#8288, fixes #8284, @alan-j-hu)

Dune 3.10.0

We're happy to announce the release of Dune 3.10.0. It comes with some internal fixes as well as some interesting features:

  • some changes in dune describe that will allow a better implementation of opam-dune-lint to check the consistency between library and package dependencies
  • more commands made available under dune show for a more consistent command line interface
See full changelog

Added

  • Add dune show rules as alias of the dune rules command. (#8000, @Alizter)

  • Add dune show installed-libraries as an alias of the dune installed-libraries command. (#8135, @Alizter)

  • Add dune build --dump-gc-stats FILE argument to dump garbage collection stats to a named file. (#8072, @Alizter)

  • Add dune describe package-entries to print all package entries (#7480, @moyodiallo)

Fixed

  • Fix %{deps} to expand properly in (cat ...) when containing 2 or more items. (#8196, @Alizter)

  • Fix the severity of error messages sent over RPC which was missing. (#8193, @Alizter)

  • Fix bug with ppx and Reason syntax due to missing dependency in sandboxed action (#7932, fixes #7930, @Alizter)

Changed

  • Improve dune describe external-lib-deps by adding the internal dependencies for more information. (#7478, @moyodiallo)

  • Re-enable background file digests on Windows. The files are now open in a way that prevents race condition around deletion. (#8262, fixes #8268, @emillon)

Feedback on this post is welcomed on Discuss!

We are happy to announce the second alpha release of opam 2.2.0. It contains some fixes and a new feature for Windows. You can view the full list in the release note.

This version is an alpha. so we invite users to test it for previously unnoticed bugs to head towards the stable release.

Windows Support

The first alpha came with native Windows compatibility. This second alpha comes with a simpler initialisation for Windows: we no longer rely on an already present Cygwin UNIX-like environment for Windows as a compatibility layer. During initialisation, opam now proposes to embed its own fully managed Cygwin install.

The main opam-repository Windows compliance is still a work in progress. We recommend using an existing, compatible repository (originally from @fdopen) and 32/64 bit mingw-w64 packages (by @dra27).

How to Test opam on Windows

This alpha requires a preexisting Cygwin installation for compiling opam.

  1. Check that you have all dependencies installed:
  • autoconf, make, patch, curl
  • MinGW compilers: mingw64-x86_64-gcc-g++, mingw64-i686-gcc-g++
  • If you want to use the MSVC port of OCaml, you'll need to install Visual Studio or Visual Studio Build Tools
  1. Download & extract the opam archive
  2. In the directory launch make cold
  3. A coffee later, you now have an opam executable!
  4. Start your preferred Windows terminal (cmd or PowerShell), and initialise opam with the Windows sunset repository:
  • opam init https://github.com/ocaml-opam/opam-repository-mingw

From here, you can try to install the sunset repository packages. If you find any bugs, please submit an issue. It will help opam-repository maintainers to add Windows repository packages into the main repository.

Hint: if you use the MinGW compiler, don't forget to add to your PATH the path to libc dlls (usually C:\cygwin64\usr\x86_64-w64-mingw32\sys-root\mingw\bin). You can also compile opam with make cold CONFIGURE_ARGS=--with-private-runtime, and if you change opam's location, don't forget to copy Opam.Runtime.amd64 (or Opam.Runtime.i386) with it.

Updates & Fixes

  • opam var now has a more informative error message in case of package variable
  • opam lint: update Error 29 on package variables on filters to check also conflicts: field
  • opam admin lint cleans output when called not from a terminal
  • configure throws an error if no complementary compiler is found on Windows

Try It!

In case you plan a possible rollback, you may want to first backup your ~/.opam directory.

The upgrade instructions are unchanged:

  1. Either from binaries, run

    bash -c "sh <(curl -fsSL https://raw.githubusercontent.com/ocaml/opam/master/shell/install.sh) --version 2.2.0~alpha2"
    

    or download manually from the Github "Releases" page to your PATH.

  2. Or from source, manually: see the instructions in the README.

You should then run:

opam init --reinit -ni

Please report any issues to the bug-tracker.

Dune 3.9.2

This bugfix-only release contains two platform-specific changes: one fixes the Dune cache on Windows, and the other one completes the fix on Linux when sendfile is not available. This makes Dune available where user directories are encrypted using ecryptfs for example.

See full changelog

Fixes

  • Disable background digests on Windows. This prevents an issue where unremovable files would make Dune crash when the shared cache is enabled. (#8243, fixes #8228, @emillon)

  • Fix permission errors when sendfile is not available (#8234, fixes #8210, @emillon)

We are thrilled to announce the release of OCamlFormat 0.26.0!

After almost 5 months of intense development, this release comes with a ton of consistency improvements and bug fixes. In particular, the handling of comments should be largely superior!

Have a look at the full changelog to see the list of improvements, and don't hesitate to share your feedback on this release on OCaml Discuss.

See full changelog

Items marked with an asterisk (*) are changes that are likely to format existing code differently from the previous release when using the default profile.

New features

  • Handle short syntax for generative functor types (#2348, @gpetiot)
  • Improved error reporting for unstable or dropped comments (#2292, @gpetiot)

Removed

  • Remove --numeric feature (#2333, #2357, @gpetiot)

Bug fixes

  • Fix crash caused by let f (type a) :> a M.u = .. (#2399, @Julow)
  • Fix crash caused by module T = (val (x : (module S))) (#2370, @Julow)
  • Fix invalid formatting of then begin end (#2369, @Julow)
  • Protect match after fun _ : _ -> (#2352, @Julow)
  • Fix invalid formatting of (::) (#2347, @Julow)
  • Fix indentation of module-expr extensions (#2323, @gpetiot)
  • * Remove double parentheses around tuples in a match (#2308, @Julow)
  • * Remove extra parentheses around module packs (#2305, @Julow, @gpetiot)
  • Fix indentation of trailing double-semicolons (#2295, @gpetiot)
  • Fix formatting of comments in "disable" chunks (#2279, @gpetiot)
  • Fix non-stabilizing comments attached to private/virtual/mutable keywords (#2272, #2307, @gpetiot, @Julow)

Changes

  • Improve formatting of doc-comments (#2338, #2349, #2376, #2377, #2379, #2378, @Julow) Remove unnecessary escaping and preserve empty lines.
  • * Indent as-patterns that have parentheses (#2359, @Julow)
  • Don't print warnings related to odoc code-blocks when '--quiet' is set (#2336, #2373, @gpetiot, @Julow)
  • * Improve formatting of module arguments (#2322, @Julow)
  • * Don't indent attributes after a let/val/external (#2317, @Julow)
  • Consistent indentation of @@ let+ x = ... (#2315, #2396, @Julow) It was formatted differently than @@ let x = ....
  • * Improve formatting of class expressions and signatures (#2301, #2328, #2387, @gpetiot, @Julow)
  • * Consistent indentation of fun (type a) -> following fun x -> (#2294, @Julow)
  • * Restore short-form formatting of record field aliases (#2282, #2388, @gpetiot, @Julow)
  • * Restore short-form for first-class modules: ((module M) : (module S)) is formatted as (module M : S)) (#2280, #2300, @gpetiot, @Julow)
  • * Improve indentation of ~label:(fun ... (#2271, #2291, #2293, #2298, #2398, @Julow) The fun keyword is docked where possible and the arguments are indented to avoid confusion with the body.
  • JaneStreet profile: treat comments as doc-comments (#2261, #2344, #2354, #2365, #2392, @gpetiot, @Julow)
  • Tweaks the JaneStreet profile to be more consistent with ocp-indent (#2214, #2281, #2284, #2289, #2299, #2302, #2309, #2310, #2311, #2313, #2316, #2362, #2363, @gpetiot, @Julow)

Utop 2.13.1

The release of UTop 2.13.0 introduced a regression on Windows. We're releasing UTop 2.13.1 with a patch, and made UTop 2.13.0 unavailable on Windows.

See full changelog
  • Fix unavailable expunge on Windows (#447, @jonahbeckford)

Dune 3.9.1

In Dune 3.9.0, we added a feature that offloads some computations to background threads. Unfortunately, this has a bad interaction on macOS, where we fork processes to implement the RPC server and watch mode.

We marked Dune 3.9.0 unavailable on macOS, and released 3.9.1 with some mitigations: we don't offload these computations on macOS, and we only fork when necessary.

The plan for the next release is to stop forking processes on macOS.

See full changelog

Fixes

  • Disable background operations and threaded console on macOS and other Unixes where we rely on fork. (#8100, #8121, fixes #8083, @rgrinberg, @emillon)

  • Initialize async I/O thread lazily. (#8122, @emillon)

Utop 2.13.0

We're releasing version 2.13.0 of UTop! This version comes with a couple of bug fixes.

It also bumps the minimal required version of OCaml to 4.11.0 and removes deprecated values from the API.

See full changelog
  • Fix behavior of utop -stdin (#434, fixes #433, @tuohy)

  • Handle bounds with Zed.next_error (#442, @tmattio)

  • Load files from XDG directories (the legacy paths still work). (#431, @Skyb0rg007)

  • Remove deprecated values prompt_continue, prompt_comment, smart_accept, new_prompt_hooks, at_new_prompt (#427, @emillon)

  • Require OCaml 4.11.0 or newer. (#444, @emillon)

Feedback on this post is welcomed on Discuss!

We are happy to announce the alpha release of opam 2.2.0. It contains numerous fixes, enhancements, and updates; including much-improved Windows support, addressing one of the most important pain points identified by the OCaml community. You can view the full list of changes in the release note.

This alpha release is a significant milestone, brought together by Raja Boujbel after years of work from the opam dev team (Raja Boujbel, David Allsopp, Kate Deplaix, Louis Gesbert, in a united OCamlPro/Tarides collaboration) with the help of many community contributors. We also thank Jane Street for their continued sponsorship.

This version is an alpha, so we invite users to test it to spot previously unnoticed bugs and work towards a stable release.

Windows Support

Opam 2.2 comes with native Windows compatibility. You can now use opam from your preferred Windows terminal! We rely on the Cygwin UNIX-like environment for Windows as a compatibility layer, but it is possible for a package to generate native executables.

The main opam repository is not Windows compatible at the moment, but existing work on a compatible repository (originally from @fdopen) and 32/64 bit mingw-w64 packages (by @dra27) is in the process of being merged. Before the final release, we expect it to be possible to run opam init and use the main opam-repository for Windows.

How to Test opam on Windows

This alpha requires a preexisting Cygwin installation. Support for full management of a local Cygwin environment inside of opam (so that it's as transparent as possible) is queued already and should be available in 2.2.0~alpha2 as the default option.

  1. Check that you have all dependencies installed:
  • autoconf, make, patch, curl
  • MinGW compilers: mingw64-x86_64-gcc-g++, mingw64-i686-gcc-g++
  • Or if you want to use the MSVC port of OCaml, you'll need to install Visual Studio or Visual Studio Build Tools
  1. Download & extract the opam archive
  2. In the directory launch make cold
  3. A coffee later, you now have an opam executable!
  4. Start your preferred Windows terminal (cmd or PowerShell), and initialise opam with the Windows sunset repository:
  • opam init https://github.com/ocaml-opam/opam-repository-mingw

From here, you can try to install sunset repository packages. If any bug is found, please submit an issue. It will help opam repository maintainers to add Windows repository packages into the main repository.

Hint: if you use the MinGW compiler, don't forget to add to your PATH the path to libc dlls (usually C:\cygwin64\usr\x86_64-w64-mingw32\sys-root\mingw\bin). Or compile opam with make cold CONFIGURE_ARGS=--with-private-runtime, and if you change opam location, don't forget to copy Opam.Runtime.amd64 (or Opam.Runtime.i386) with it.

Recursive Pin

When installing or pinning a package using opam install or opam pin, opam normally only looks for opam files at the root of the installed package. With recursive pinning, you can now instruct opam to also look for .opam files in subdirectories, while maintaining the correct relationship between the .opam files and the package root for versioning and build purposes.

Recursive pinning is used with the following options to opam pin and opam install:

  • With --recursive, opam will look for .opam files recursively in all subdirectories.
  • With --subpath <path>, opam will only look for .opam files in the subdirectory <path>.

The two options can be combined: for instance, if your opam packages are stored as a deep hierarchy in the mylib subdirectory of your project, give opam pin . --recursive --subpath mylib a try!

You can use these options with opam pin, opam install, and opam remove.

$ tree .
.
├── ba
│   └── z
│       └── z.opam
├── bar
│   └── bar.opam
└── foo.opam

$ opam pin . --subpath ba/z --no-action
Package z does not exist, create as a NEW package? [y/n] y
z is now subpath-pinned to directory /ba/z in git+file:///tmp/recpin#master (version 0.1)

$ opam pin --recursive . --no-action
This will pin the following packages: foo, z, bar. Continue? [y/n] y
foo is now pinned to git+file:///tmp/recpin#master (version 0.1)
Package z does not exist, create as a NEW package? [y/n] y
z is now subpath-pinned to directory /ba/z in git+file:///tmp/recpin#master (version 0.1)
Package bar does not exist, create as a NEW package? [y/n] y
bar is now subpath-pinned to directory /bar in file:///tmp/recpin (version 0.1)

$ opam pin
bar.0.1  (uninstalled)  rsync  directory /bar in file:///tmp/recpin
foo.0.1  (uninstalled)  git    git+file:///tmp/recpin#master
z.0.1    (uninstalled)  git    directory /ba/z in git+file:///tmp/recpin#master

$ opam pin . --recursive --subpath ba/ --no-action
Package z does not exist, create as a NEW package? [y/n] y
z is now subpath-pinned to directory /ba/z in git+file:///tmp/recpin#master (version 0.1)

Tree View

opam tree shows packages and their dependencies with a tree view. It is very helpful to determine which packages bring which dependencies in your installed switch.

$ opam tree cppo
cppo.1.6.9
├── base-unix.base
├── dune.3.8.2 (>= 1.10)
│   ├── base-threads.base
│   ├── base-unix.base [*]
│   └── ocaml.4.14.1 (>= 4.08)
│       ├── ocaml-base-compiler.4.14.1 (>= 4.14.1~ & < 4.14.2~)
│       └── ocaml-config.2 (>= 2)
│           └── ocaml-base-compiler.4.14.1 (>= 4.12.0~) [*]
└── ocaml.4.14.1 (>= 4.02.3) [*]

It can also display a reverse-dependency tree (through opam why, which is an alias to opam tree --rev-deps). This is useful to examine how dependency versions get constrained.

$ opam why cmdliner
cmdliner.1.2.0
├── (>= 1.1.0) b0.0.0.5
│   └── (= 0.0.5) odig.0.0.9
├── (>= 1.1.0) ocp-browser.1.3.4
├── (>= 1.0.0) ocp-indent.1.8.1
│   └── (>= 1.4.2) ocp-index.1.3.4
│       └── (= version) ocp-browser.1.3.4 [*]
├── (>= 1.1.0) ocp-index.1.3.4 [*]
├── (>= 1.1.0) odig.0.0.9 [*]
├── (>= 1.0.0) odoc.2.2.0
│   └── (>= 2.0.0) odig.0.0.9 [*]
├── (>= 1.1.0) opam-client.2.2.0~alpha
│   ├── (= version) opam.2.2.0~alpha
│   └── (= version) opam-devel.2.2.0~alpha
├── (>= 1.1.0) opam-devel.2.2.0~alpha [*]
├── (>= 0.9.8) opam-installer.2.2.0~alpha
└── user-setup.0.7

Special thanks to @cannorin for contributing this feature.

Recommended Development Tools

There is now a way for a project maintainer to share their project development tools: the with-dev-setup dependency flag. It is used in the same way as with-doc and with-test: by adding a {with-dev-setup} filter after a dependency. It will be ignored when installing normally, but it's pulled in when the package is explicitely installed with the --with-dev-setup flag specified on the command line. The variable is also resolved in the post-messages: field to allow maintainers to share more informations about that setup.

This is typically useful for tools that are required for bootstrapping or regenerating artifacts.

For example

opam-version: "2.0"
depends: [
  "ocaml"
  "dune"
  "ocp-indent" {with-dev-setup}
]
build: [make]
install: [make "install"]
post-messages:
[ "Thanks for installing the package"
  "and its tool dependencies too, it will help for your futur PRs" {with-dev-setup} ]

Software Heritage Binding

Software Heritage is a project that aims to archive all software source code in existence. This is done by collecting source code with a loader that uploads software source code to the Software Heritage distributed infrastructure. From there, any project/version is available via the search webpage and via a unique identifier called the SWHID. Some OCaml source code is already archived, and the main opam and Coq repository packages are continuously uploaded.

Opam now integrates a fallback to Software Heritage archive retrieval, based on SWHID. If an SWHID URL is present in an opam file, the fallback can be activated.

To keep backwards compatibility of opam files, we added a specific Software Heritage URL syntax to the url.mirrors: field, which is used to specify mirrors of the main URL. Opam 2.2.+ understands this specific syntax as a Software Heritage fallback URL: https://swhid.opam.ocaml.org/<SWHID>.

url {
  src: "https://faili.ng/url.tar.gz"
  checksum: "sha512=e2146c1d7f53679fd22df66c9061b5ae4f8505b749513eedc67f3c304f297d92e54f5028f40fb5412d32c7d7db92592eacb183128d2b6b81d10ea716b7496eba"
  mirrors: [
    "https//failli.ng/mirror.tar.gz"
    "https://swhid.opam.ocaml.org/swh:1:dir:9f2be900491e1dabfc027848204ae01aa88fc71d"
  ]
}

To add a Software Heritage fallback URL to your package, use the swhid library. Specifically the Compute.directory_identifier_deep function:

  1. Download opam package archive
  2. Extract the archive
  3. Compute SWHID with Compute.directory_identifier_deep. You can use this oneliner in the directory:
ocaml -e '#use "topfind";; #require "digestif.ocaml";; #require "swhid";; Swhid_core.Object.pp Format.std_formatter (Result.get_ok (Swhid.Compute.directory_identifier_deep "."))'

Special thanks to @zapashcanon for collaborating on this feature.

Formula (Experimental)

It is now possible to leverage the full expressivity of package dependency formulas from the command line during switch creation and package operations.

It is possible to create a switch using a formula. For example, with ocaml-variant or ocaml-system, excluding ocaml-base-compiler:

opam switch create ocaml --formula '"ocaml-variants" {>= "4.14.1"} | "ocaml-system"'

This syntax is brought to install commands. For example, while installing a package, let's say genet, you can specify that you want to install either conf-mariadb & mariadb or conf-postgresql:

opam install genet --formula '["mysql" ("conf-mariadb" & "mariadb" | "conf-postgresql")]'

New Options

Here are several of new options (possibly scripts breaking changes are marked with ✘):

  • opam pin --current to fix a package to its current state (disabling pending reinstallations or removals from the repository). The installed package will be pinned with the opam file that is stored in opam internal state, the one that is currently installed.

  • opam pin remove --all to remove all the pinned packages from a switch.

  • opam pin remove pkg.version now removes the pins on pinned pkg.version.

  • opam exec --no-switch to remove opam environment from launched command.

$ export FOOVAR=env
$ opam show foo --field setenv
FOOVAR = "package"
$ opam exec  -- env | grep "OPAM_SWITCH\|FOO"
FOOVAR=package
OPAM_SWITCH_PREFIX=~/.opam/env
$ opam exec --no-switch -- env | grep "OPAM_SWITCH\|FOO"
FOOVAR=env
  • opam source --no-switch to allow downloading package sources without having an installed switch (instead of failing).

  • opam clean --untracked to remove untracked files interactively remaining from previous packages removal.

  • opam switch -, inspired from git switch -, that goes back to the previously selected global switch.

  • opam admin add-constraint <cst> --packages pkg1,pkg2,pkg3 to select a subset of packages to apply constraints.

  • ✘ Change --base into --invariant. opam switch compiler column now contains installed packages that verifies invariant formula, and empty synopsis shows switch invariant.

$ opam switch create inv --formula '["ocaml" {>= "4.14.1"} "dune"]'
$ opam switch invariant
["ocaml" {>= "4.14.1"} "dune"]
$ opam list --invariant
# Packages matching: invariant
# Name # Installed # Synopsis
dune   3.8.2       Fast, portable, and opinionated build system
ocaml  5.0.0       The OCaml compiler (virtual package)
$ opam switch list
#  switch   compiler                                            description
→  inv      ocaml-base-compiler.5.0.0,ocaml-options-vanilla.1   ocaml >= 4.14.1 & dune

Try It!

In case you plan a possible rollback, you may want to first backup your ~/.opam directory.

The upgrade instructions are unchanged:

  1. From binaries: run
bash -c "sh <(curl -fsSL https://raw.githubusercontent.com/ocaml/opam/master/shell/install.sh) --version 2.2.0~alpha"

Or download manually from the Github "Releases" page to your PATH.

  1. From source, manually: see the instructions in the README.

Then run:

opam init --reinit -ni

Please report any issues to the bug-tracker.

Thanks for trying this new release out, and we're hoping you will enjoy the new features!

After two alpha releases, the release of OCaml 5.1.0 is drawing near. We have thus released a first beta version of OCaml 5.1.0 to help you update your softwares and libraries ahead of the release (see below for the installation instructions). Compared to the last alpha release, this beta contains two subtle internal runtime fixes and one Windows fix. Overall, the opam ecosystem looks in a good shape for the first beta release.

If you find any bugs, please report them on OCaml's issue tracker.

Nearly all core development tools support OCaml 5.1.0, and you can follow the last remaining wrinkles on the opam readiness for 5.1.0 meta-issue.

Currently, the release is planned for the end of July or the beginning of August.

If you are interested in full list of features and bug fixes of the new OCaml version, the updated change log for OCaml 5.1.0 is available on GitHub.


Installation Instructions

The base compiler can be installed as an opam switch with the following commands on opam 2.1:

opam update
opam switch create 5.1.0~beta1

The source code for the alpha is also available at these addresses:

Fine-Tuned Compiler Configuration

If you want to tweak the configuration of the compiler, you can switch to the option variant with:

opam update
opam switch create <switch_name> ocaml-variants.5.1.0~beta1+options <option_list>

where option_list is a space-separated list of ocaml-option-* packages. For instance, for a flambda and no-flat-float-array switch:

opam switch create 5.1.0~beta1+flambda+nffa ocaml-variants.5.1.0~beta1+options ocaml-option-flambda ocaml-option-no-flat-float-array

All available options can be listed with opam search ocaml-option.

See full changelog

Runtime System Bugfix

  • #12037: Fix some data races by using volatile when necessary (Fabrice Buoro and Olivier Nicole, review by Guillaume Munch-Maccagnoni, Gabriel Scherer and Luc Maranget)

  • #12253, #12342: Fix infinite loop in signal handling. (Guillaume Munch-Maccagnoni, report by Thomas Leonard, review by KC Sivaramakrishnan and Sadiq Jaffer)

Windows Bugfix

  • #12184, #12320: Sys.rename Windows fixes on directory corner cases. (Jan Midtgaard, review by Anil Madhavapeddy)

Dune 3.9.0

The Dune team is thrilled to announce the release of Dune 3.9.0. This version ships with a host of new features and improvements, including:

  • New dune show Command: This command enables you to display various pieces of information. For instance, you can use dune show pp to display the preprocessed output of a file or dune show aliases [DIR] to list the aliases available in DIR. Read more about the command on its manpage using dune show --help.
  • Improved Dialect Support: We have rolled out several fixes related to dialect support. These changes make it easier to work with Dream's .eml files.
  • Introduction of (build_if) Toggle in (test) Stanza: This new field facilitates the packaging of non-portable tests and benchmarks. If you have tests that don't build on a specific platform, you can now tell Dune not to build them on other Platforms with the build_if field.

Enjoy the new features and improvements incorporated into this version!

See full changelog

Added

  • Include the time it takes to read/write state files when --trace-file is enabled (#7960, @rgrinberg)

  • Include source tree scans in the traces produced by --trace-file (#7937, @rgrinberg)

  • Add --all option to dune rpc status to show all Dune RPC servers running. (#8011, fix #7902, @Alizter)

  • Add additional metadata to the traces provided by --trace-file whenever --trace-extended is passed (#7778, @rleshchinskiy)

  • $ dune describe is now a command group, so arguments to subcommands must be passed after subcommand itself. (#7919, @Alizter)

  • Add dune show command group which is an alias of dune describe. (#7946, @Alizter)

  • Add dune show env command and make dune printenv an alias of it. (#7985, @Alizter)

  • Add commands dune show targets and dune show aliases that display all the available targets and aliases in a given directory respectively. (#7770, grants #265, @Alizter)

  • Extensions used in (dialect) can contain periods (e.g., cppo.ml). (#7782, fixes #7777, @nojb)

  • The interface and implementation fields of a (dialect) are now optional (#7757, @gpetiot)

  • Add (build_if) to the (test) stanza. When it evaluates to false, the executable is not built. (#7899, fixes #6938, @emillon)

  • Allow (include_subdirs qualified) to be used when libraries define a (modules ...) field (#7797, fixes #7597, @anmonteiro)

  • Allow multiple globs in library's (stdlib (internal_modules ..)) (@anmonteiro, #7878)

Changed

  • Do not rerun OCaml syntax files on every iteration of the watch mode. This is too memory consuming. (#7894, fix #6900, @rgrinberg)

  • Attach melange rules to the default alias (#7926, @haochenx)

  • Compute digests and manage sandboxes in background threads (#7947, @rgrinberg)

Fixed

  • Validate file extension for $ dune ocaml top-module. (#8005, fixes #8004, @3Rafal)

  • Cinaps: The promotion rules for cinaps would only offer one file at a time no matter how many promotions were available. Now we offer all the promotions at once (#7901, @rgrinberg)

  • Add necessary parentheses in generated opam constraints (#7682, fixes #3431, @Lucccyo)

Removed

  • Remove some compatibility code for old version of dune that generated .merlin files. Now dune will never remove .merlin files automatically (#7562)

  • In opam constraints, reject (and) and (or) with no arguments at parse time (#7730, @emillon)

The OCaml infrastructure team is going to move to Debian 12 as the main distribution from Debian 11. We will continue to provide Debian 11 and 10 images while they are supported, dropping Debian 10 when it reaches end of life in 2024-06-30. In addition to these changes we are deprecating Ubuntu 18.04, Alpine 3.16/17, OL7, OpenSuse 15.2 distributions as the have reached end of life. We strongly recommend updating to a newer version if you are still using them.

Please get in touch on https://github.com/ocaml/infrastructure/issues if you have questions or requests for additional support.

See full changelog
  • OCaml Debian images upgraded to Debian 12 (ocaml-dockerfile#172, @MisterDA)
  • Deprecation of Ubuntu 18.04, Alpine 3.16 and 3.17, OracleLinux 7, OpenSUSE 15.2 images (ocaml-dockerfile#176, @avsm)
  • Deprecate Ubuntu 18.04, Alpine 3.16/17, OL7, OpenSuse 15.2 for OCaml-CI (ocaml-ci#832, @tmcgilchrist)
  • Deprecate Ubuntu 18.04, Alpine 3.16/17, OL7, OpenSuse 15.2 for opam-repo-ci (opam-repo-ci#226, @tmcgilchrist)
  • Deprecate Ubuntu 18.04, Alpine 3.16/17, OL7, OpenSuse 15.2 for docker-base-images (docker-base-images#237, @tmcgilchrist)

Dune 3.8.3

This point release fixes two important issues on Windows and Linux.

See full changelog
  • Fix deadlock on Windows (dune#8044, @nojb)
  • When using sendfile to copy files on Linux, fall back to the portable version if it fails at runtime for some reason (NFS, etc). (dune#8049, fixes dune#8041, @emillon)

We're excited to announce the release of Dune-release 2.0.0!

This release brings support for putting your .opam files in a opam/ directory. If your project contains dozens of packages, you'll be able to generate them into the opam/ folder starting with Dune 3.8 using (opam_file_location inside_opam_directory) in your dune-project.

Another notable change is the removal of delegates. Users of dune-release who want to publish their packages to another platform than GitHub can now use the dune-release delegate-info and use the output to build their own publication workflows.

See full changelog

Added

  • Adopt the OCaml Code of Conduct (#473, @rikusilvola)
  • Added support for projects that have their OPAM files in the opam/ subdirectory. (#466, @Leonidas-from-XIV)

Changed

  • Running dune-release check now attempts to discover and parse the change log, and a new flag --skip-change-log disables this behaviour. (#458, @gridbugs)
  • List the main package and amount of subpackages when creating the PR to avoid very long package lists in PRs (#465, @emillon)

Fixed

  • Avoid collision between branch and tag name. Tag detection got confused when branch was named the same as tag. Now it searches only for tag refs, instead of all refs. (#452, @3Rafal)
  • Fix project name detection from dune-project. The parser could get confused when opam file generation is used. Now it only considers the first (name X) in the file. (#445, @emillon)

Removed

  • Remove support for delegates. Previous users of this feature should now use dune-release delegate-info and wrap dune-release calls in a script. See #188 for details. (#428, @NathanReb)
  • Removed support for the OPAM 1.2.2 client. This means dune-release expects the opam binary to be version 2.0 at least. (#406, #411, @Leonidas-from-XIV)

We've released OCaml LSP 1.16.2 with a fix that was introduced in 1.16.1 that prevented users from using preprocessor such as CPPO.

See full changelog

Fixes

  • Fix file permissions used when specifying output files of pp and ppx. (ocaml-lsp#1153)

We're thrilled to announce the release of OCaml LSP 1.16.1! 🎉

This release comes with new "Extract local" and "Extract function" code actions to easily refactor your code.

We've also disabled code lenses by default following user feedback. You can follow the discussion on GitHub.

This release is also the first OCaml LSP release to use upstream Merlin. Among other things, this means that it is compatible with all the OCaml versions supported by Merlin: currently OCaml 4.14 and 5.0.0.

We're also releasing numerous bug fixes, including:

  • A fix to the integration with Dune RPC on Windows, which, alongside Dune 3.9.0, makes OCaml LSP report Dune errors to the editors with Dune watch mode enabled.
  • Minor improvements to the Odoc <-> Markdown conversion to return better function documentation on the editor.

And much more! Read the full changelog for a complete list of improvements and bug fixes.

See full changelog

Features

  • Add "Remove type annotation" code action. (#1039)
  • Support settings through didChangeConfiguration notification (#1103)
  • Add "Extract local" and "Extract function" code actions. (#870)
  • Depend directly on merlin-lib 4.9 (#1070)

Fixes

  • Support building with OCaml 5.0 and 5.1 (#1150)

  • Disable code lens by default. The support can be re-enabled by explicitly setting it in the configuration. (#1134)

  • Fix initilization of ocamlformat-rpc in some edge cases when ocamlformat is initialized concurrently (#1132)

  • Kill unnecessary $ dune ocaml-merlin with SIGTERM rather than SIGKILL (#1124)

  • Refactor comment parsing to use odoc-parser and cmarkit instead of octavius and omd (#1088)

    This allows users who migrated to omd 2.X to install ocaml-lsp-server in the same opam switch.

    We also slightly improved markdown generation support and fixed a couple in the generation of inline heading and module types.

  • Allow opening documents that were already open. This is a workaround for neovim's lsp client (#1067)

  • Disable type annotation for functions (#1054)

  • Respect codeActionLiteralSupport capability (#1046)

  • Fix a document syncing issue when utf-16 is the position encoding (#1004)

  • Disable "Type-annotate" action for code that is already annotated. (#1037, fixes #1036)

  • Fix semantic highlighting of long identifiers when using preprocessors (#1049, fixes #1034)

  • Fix the type of DocumentSelector in cram document registration (#1068)

  • Accept the --clientProcessId command line argument. (#1074)

  • Accept --port as a synonym for --socket. (#1075)

  • Fix connecting to dune rpc on Windows. (#1080)

Ppxlib 0.30.0

We're excited to announce the release of Ppxlib 0.30.0! It comes with support for OCaml 5.1, various enhancements, and bug fixes.

For PPX writing, Ast_pattern now offers additional utility functions, while metaquot benefits from improved error reporting.

PPX usage sees better compatibility with OCaml trunk, thanks to the Driver's improved Parsetree version recognition. This allows for compatibility with both trunk and stable OCaml versions concurrently.

Finally, this release enhances Ppxlib's compatibility with ReScript, introducing "ns" and "res" as reserved namespaces.

See full changelog

Dune 3.8.2

We've released Dune 3.8.2 with a few bug fixes.

See full changelog
  • Switch back to threaded console for all systems; fix unresponsive console on Windows (dune#7906, @nojb)
  • Respect -p / --only-packages for melange.emit artifacts (dune#7849, @anmonteiro)
  • Fix scanning of Coq installed files (@ejgallego, reported by @palmskog, dune#7895 , fixes dune#7893)
  • Fix RPC buffer corruption issues due to multi threading. This issue was only reproducible with large RPC payloads (dune#7418)
  • Fix printing errors from excerpts whenever character offsets span multiple lines (dune#7950, fixes dune#7905, @rgrinberg)

The server toxis where Opam-Repo-CI and OCaml-CI were deployed suffered hardware difficulties yesterday, resulting in BTRFS filesystem corruption and memory issues. These issues are tracked on ocaml/infrastructure#51. Services were restored temporarily using a spare spinning disk, but we continued to see ECC memory issues.

All services have now been redeployed on new ARM64 hardware. We retained the databases for Prometheus, OCaml-CI and Opam-Repo-CI, but unfortunately, older job logs have been lost.

The external URLs for these services are unchanged.

Dune 3.8.1

We've just released a patch version of Dune to fix regressions introduced in Dune 3.8.0.

In particular, we've reverted some cross-compilation improvements that caused build failures when using ppx_runtime_libraries and we'll revisit them in a future version of Dune.

See full changelog
  • Fix a crash when using a version of Coq < 8.13 due to the native compiler config variable being missing. We now explicitly default to (mode vo) for these older versions of Coq. (dune#7847, fixes dune#7846, @Alizter)
  • Duplicate installed Coq theories are now allowed with the first appearing in COQPATH being preferred. This is inline with Coq's loadpath semantics. This fixes an issue with install layouts based on COQPATH such as those found in nixpkgs. (dune#7790, @Alizter)
  • Revert dune#7415 and dune#7450 (Resolve ppx_runtime_libraries in the target context when cross compiling) (dune#7887, fixes dune#7875, @emillon)

With the progress of the ongoing stabilisation effort for OCaml 5.1.0, I am happy to announce a second alpha release for OCaml 5.1.0.

This second alpha release contains many noteworthy fixes:

  • a long-awaited GC fix
  • a Windows ABI fix

as announced in the first alpha but also

  • a compiler-libs (parsetree) fix
  • a type system compatibility enhancement change
  • a restored backed for s390x/IBM Z

The full list of changes since the first alpha is available below.

Once most major OCaml tools are updated to the last compiler-libs changes, we will switch to beta releases. Hopefully, this will happen in the upcoming weeks. The progress on stabilising the ecosystem is tracked on the opam readiness for 5.1.0 meta-issue.

Currently, the release is still planned for around July.

If you find any bugs, please report them on OCaml's issue tracker.

If you are interested in the ongoing list of new features and bug fixes, the updated change log for OCaml 5.1.0 is available on GitHub.


Installation Instructions

The base compiler can be installed as an opam switch with the following commands on opam 2.1:

opam update
opam switch create 5.1.0~alpha2

The source code for the alpha is also available at these addresses:

Fine-Tuned Compiler Configuration

If you want to tweak the configuration of the compiler, you can switch to the option variant with:

opam update
opam switch create <switch_name> ocaml-variants.5.1.0~alpha2+options <option_list>

where option_list is a space-separated list of ocaml-option-* packages. For instance, for a flambda and no-flat-float-array switch:

opam switch create 5.1.0~alpha2+flambda+nffa ocaml-variants.5.1.0~alpha2+options ocaml-option-flambda ocaml-option-no-flat-float-array

All available options can be listed with opam search ocaml-option.

See full changelog

Runtime System

  • #11589, #11903: Modify the GC pacing code to make sure the GC keeps up with allocations in the presence of idle domains. (Damien Doligez and Stephen Dolan, report by Florian Angeletti, review by KC Sivaramakrishnan and Sadiq Jaffer)
  • (breaking change) #11865, #11868, #11876: Clarify that the operations of a custom block must never access the OCaml runtime. The previous documentation only mentioned the main illicit usages. In particular, since OCaml 5.0, it is no longer safe to call caml_remove_global_root or caml_remove_generational_global_root from within the C finalizer of a custom block, or within the finalization function passed to caml_alloc_final. As a workaround, such a finalization operation can be registered with Gc.finalize instead, which guarantees to run the finalizer at a safe point. (Report by Timothy Bourke, discussion by Yotam Barnoy, Timothy Bourke, Sadiq Jaffer, Xavier Leroy, Guillaume Munch-Maccagnoni, and Gabriel Scherer)
  • #11827, +#12249: Restore prefetching for GC marking (Fabrice Buoro and Stephen Dolan, review by Gabriel Scherer and Sadiq Jaffer)
  • #12131: Simplify implementation of weak hash sets, fixing a performance regression. (Nick Barnes, review by François Bobot, Alain Frisch and Damien Doligez).

  • #12231: Support MinGW-w64 11.0 winpthreads library, where the macro to set up to get flexdll working changed (David Allsopp and Samuel Hym, light review by Xavier Leroy)

Type System

  • (breaking change) #12189, #12211: anonymous row variables in explicitly polymorphic type annotation, e.g. 'a. [< X of 'a ] -> 'a, are now implicitly universally quantified (in other words, the example above is now read as 'a 'r. ([< X of 'a ] as 'r) -> 'a). (Florian Angeletti and Gabriel Scherer, review by Jacques Garrigue)

Code Generation And Optimizations

  • #11712, #12258, #12261: s390x / IBM Z multicore support: OCaml & C stack separation; dynamic stack size checks; fiber and effects support. (Aleksei Nikiforov, with help from Vincent Laviron and Xavier Leroy, additional suggestions by Luc Maranget, review by the same and KC Sivaramakrishnan)

Internal/compiler-libs Changes

  • #12119, +#12188, +#12191: mirror type constraints on value binding in the parsetree: the constraint typ in let pat : typ = exp is now directly stored in the value binding node in the parsetree. (Florian Angeletti, review by Richard Eisenberg)

Bug Fixes

  • #11846: Mark rbx as destroyed at C call for Win64 (mingw-w64 and Cygwin64). Reserve the shadow store for the ABI in the c_stack_link struct instead of explictly when calling C functions. This simultaneously reduces the number of stack pointer manipulations and also fixes a bug when calling noalloc functions where the shadow store was not being reserved. (David Allsopp, report by Vesa Karvonen, review by Xavier Leroy and KC Sivaramakrishnan)

  • #12170: fix pthread_geaffinity_np configure check for android (David Allsopp, review by Sébastien Hinderer)

  • #12252: Fix shared library build error on RISC-V. (Edwin Török, review by Nicolás Ojeda Bär and Xavier Leroy)

  • #12255, #12256: Handle large signal numbers correctly (Nick Barnes, review by David Allsopp).

  • #12277: ARM64, fix a potential assembler error for very large functions by emitting stack reallocation code before the body of the function. (Xavier Leroy, review by KC Sivaramakrishnan)

opam 2.1.5

Feedback on this post is welcomed on Discuss!

We are pleased to announce the patch release of opam 2.1.5.

This opam release consists of backported bug & security fixes:

  • Security issue: fix opam installing packages without checking their checksum when the local cache is corrupted in some case (#5538), you can find more information there.
  • Variables are now expanded in build-env (as for setenv) (#5352)
  • Correctly handle empty environment variable additions (#5350)
  • Skip empty environment variable additions (#5350)
  • Fix passing archive-mirrors field from init config file to config (#5315)
  • git, hg: Use the full SHA1 revision instead of just the 8 first characters (#5342)

Opam installation instructions (unchanged):

  1. From binaries: run

    bash -c "sh <(curl -fsSL https://raw.githubusercontent.com/ocaml/opam/master/shell/install.sh) --version 2.1.5"
    

    or download manually from the Github "Releases" page to your PATH. In this case, don't forget to run opam init --reinit -ni to enable sandboxing if you had version 2.0.0~rc manually installed or to update you sandbox script.

  2. From source, using opam:

    opam update; opam install opam-devel
    

    (then copy the opam binary to your PATH as explained, and don't forget to run opam init --reinit -ni to enable sandboxing if you had version 2.0.0~rc manually installed or to update your sandbox script)

  3. From source, manually: see the instructions in the README.

We hope you enjoy this new minor version, and remain open to bug reports and suggestions.

Merlin 4.9

We are pleased to announce the release of Merlin 4.9 for OCaml 4.14.1 and 5.0.

This maintenance release brings multiple bug fixes and improvements. In particular we identified and patched an important memory consumption issue that could greatly affect Merlin’s performance in heavily functorized projects.

See full changelog
  • merlin binary
    • Allow monadic IO in dot protocol (#1581)
    • Add a scope option to the occurrences command in preparation for the upcoming project-wide-occurrences feature (#1596)
    • Construct bool-typed holes as false instead of true in the construct command, for consistency (#1599).
    • Add a hook to configure system command for spawning ppxes when Merlin is used as a library. (#1585)
    • Implement an all-or-nothing cache for the PPX phase (#1584)
    • Cleanup functors caches when backtracking, to avoid memory leaks (#1609, fixes #1529 and ocaml-lsp#1032)
    • Fix construct results ordering for sum types sand poly variants (#1603)
    • Fix object method completion not working (#1606, fixes #1575)
    • Improve context detection for package types (#1608, fixes #1607)
    • Fix incorrect locations for string literals (#1574)
    • Fixed an issue that caused errors to erroneously alert about missing cmi files (#1577)
    • Prevent destruct from crashing on closed variant types (#1602, fixes #1601)
    • Improve longident parsing (#1612, fixes #945)
  • editor modes
    • emacs: call the user's configured completion UI in merlin-construct (#1598)
  • test suite
    • Add missing dependency to a test using ppxlib (#1583)
    • Add tests for the new PPX phase cache (#1584)
    • Add and update tests for construct ordering (#1603)

Dune 3.8.0

The dune team is pleased to announce the release of Dune 3.8.0.

It is now available in opam-repository. As usual, it should always be safe to upgrade your dune package: new features and deprecations are only available if you upgrade the language version in your dune-project files.

🌟 Spotlight Features

  1. Dune concurrent action

Dune 3.8.0 introduced the new concurrent action. You can now use it instead of the progn action to execute actions concurrently.

For instance:

(rule
(action
  (concurrent
  (write-file A "I am file A.\n")
  (write-file B "I am certainly file B.\n")
  (write-file C "I am most certainly file C.\n"))))

will write to files A, B and C concurrently.

  1. Support for .mld files

In Dune 3.7.0, we introduced version 0.3 of the mdx stanza, which came with support for .mld files.

In Dune 3.8.0, .mld files are now supported by default with version 0.4 of the mdx stanza!

Have a look at this diff to see how to migrate your code to the new stanza version.

See full changelog

Added

  • Introduce mdx stanza 0.4 requiring mdx >= 2.3.0 which updates the default list of files to include *.mld files (#7582, @Leonidas-from-XIV)

  • Allow (stdlib ...) to be used with (wrapped false) in library stanzas (#7139, @anmonteiro).

  • Allow the main module of a library with (stdlib ...) to depend on other libraries (#7154, @anmonteiro).

  • Support (link_flags ...) in (cinaps ...) stanza. (#7423, fixes #7416, @nojb)

  • Allow (package ...) in any position within (rule ...) stanza (#7445, @Leonidas-from-XIV)

  • Added a new user action (concurrent ) which is like (progn ) but runs the actions concurrently. (#6933, @Alizter)

  • Accept the Ordered Set Language for the modes field in library stanzas (#6611, @anmonteiro).

  • Allow parallel execution of inline tests partitions (#7012, @hhugo)

  • Add the --display-separate-messages flag to separate the error messages produced by commands with a blank line. (#6823, fixes #6158, @esope)

  • Add --watch-exclusions to Dune build options (#7216, @jonahbeckford)

  • Adds support for loading plugins in toplevels (#6082, fixes #6081, @ivg, @richardlford)

  • Introduce a public_headers field on libraries. This field is like install_c_headers, but it allows to choose the extension and choose the paths for the installed headers. (#7512, @rgrinberg)

  • Dune can now detect Coq theories from outside the workspace. This allows for composition with installed theories (not necessarily installed with Dune). (#7047, @Alizter, @ejgallego)

  • Added a --no-build option to dune coq top for avoiding rebuilds (#7380, fixes #7355, @Alizter)

  • Add a coqdoc_flags field to the coq.theory stanza allowing the user to pass extra arguments to coqdoc. (#7676, fixes #7954 @Alizter)

  • Preliminary support for Coq compiled intefaces (.vos files) enabled via (mode vos) in coq.theory stanzas. This can be used in combination with dune coq top to obtain fast re-building of dependencies (with no checking of proofs) prior to stepping into a file. (#7406, @rlepigre)

  • Read pkg-config arguments from the PKG_CONFIG_ARGN environment variable (#1492, #7734, @anmonteiro)

  • Use $PKG_CONFIG, when set, to find the pkg-config binary (#7469, fixes #2572, @anmonteiro)

Changed

  • Bootstrap: remove reliance on shell. Previously, we'd use the shell to get the number of processors. (#7274, @rgrinberg)

  • Non-user proccesses such as version control or config checking are now run silently. (#6994, fixes #4066, @Alizter)

  • Bytecode executables built for JSOO are linked with -noautolink and no longer depend on the shared stubs of their dependent libraries (#7156, @nojb)

  • Always include opam files in the generated .install file. Previously, it would not be included whenever (generate_opam_files true) was set and the .install file wasn't yet generated. (#7547, @rgrinberg)

Deprecated

  • Modules that were declared in (modules_without_implementation), (private_modules) or (virtual_modules) but not declared in (modules) will cause Dune to emit a warning which will become an error in 3.9. (#7608, fixes #7026, @Alizter)

  • Coq language versions less 0.8 are deprecated, and will be removed in an upcoming Dune version. All users are required to migrate to (coq lang 0.8) which provides the right semantics for theories that have been globally installed, such as those coming from opam (@ejgallego, @Alizter)

Fixed

  • Find pps dependencies in the host context when cross-compiling, (#7415, fixes #4156, @anmonteiro)

  • Fix plugin loading with findlib. The functionality was broken in 3.7.0. (#7556, @anmonteiro)

  • Load the host context findlib.conf when cross-compiling (#7428, fixes #1701, @rgrinberg, @anmonteiro)

  • Allow overriding the ocaml binary with findlib configuration (#7648, @rgrinberg)

  • Resolve ppx_runtime_libraries in the target context when cross compiling (#7450, fixes #2794, @anmonteiro)

  • Fix dune install when cross compiling (#7410, fixes #6191, @anmonteiro, @rizo)

  • Fix string quoting in the json file written by --trace-file (#7773, @rleshchinskiy)

  • Correctly set MANPATH in dune exec. Previously, we would use the bin/ directory of the context. (#7655, @rgrinberg)

  • merlin: ignore instrumentation settings for preprocessing. (#7606, fixes #7465, @Alizter)

  • When a rule's action is interrupted, delete any leftover directory targets. This is consistent with how we treat file targets. (#7564, @rgrinberg)

  • Fix dune crashing on MacOS in watch mode whenever $PATH contains $PWD (#7441, fixes #6907, @rgrinberg)

  • Dune in watch mode no longer builds concurrent rules in serial (#7395 @rgrinberg, @jchavarri)

  • dune coq top now correctly respects the project root when called from a subdirectory. However, absolute filenames passed to dune coq top are no longer supported (due to being buggy) (#7357, fixes #7344, @rlepigre and @Alizter)

  • RPC: Ignore SIGPIPE when clients suddenly disconnect (#7299, #7319, fixes #6879, @rgrinberg)

  • Always clean up the UI on exit. (#7271, fixes #7142 @rgrinberg)

  • Bootstrap: correctly detect the number of processors by allowing nproc to be looked up in $PATH (#7272, @Alizter)

  • Speed up file copying on macos by using clonefile when available (@rgrinberg, #7210)

  • Support commands that output 8-bit and 24-bit colors in the terminal (#7188, @Alizter)

  • Speed up rule generation for libraries and executables with many modules (#7187, @jchavarri)

  • Do not re-render UI on every frame if the UI doesn't change (#7186, fix #7184, @rgrinberg)

  • Make coq_db creation in scope lazy (@ejgallego, #7133)

  • dune install now respects --display quiet mode (#7116, fixes #4573, fixes #7106, @Alizter)

  • Stub shared libraries (dllXXX_stubs.so) in Dune-installed libraries could not be used as dependencies of libraries in the workspace (eg when compiling to bytecode and/or Javascript). This is now fixed. (#7151, @nojb)

  • Fix regression where Merlin was unable to handle filenames with uppercase letters under Windows. (#7577, @nojb)

  • On nix+macos, pass -f to the codesign hook to avoid errors when the binary is already signed (#7183, fixes #6265, @greedy)

  • Fix bug where RPC clients built with dune-rpc-lwt would crash when closing their connection to the server (#7581, @gridbugs)

  • Fix RPC server on Windows (used for OCaml-LSP). (#7666, @nojb)

If you want to contribute to a new release announcement, check out the Contributing Guide on GitHub.