OCaml Changelog

Fixed

• Fix include_subdirs qualified incorrectly picking the furthest module instead of the closest when resolving module name ambiguities. (#12587, @ElectreAAS and @Alizter)

• Fix: include the module alias in the transitive dependency closure with (include_subdirs qualified). (#12299, @anmonteiro)

• Improve error messages for invalid version formats containing non-ASCII characters. Previously, non-ASCII characters in version strings (e.g., (lang dune è) or (using menhir π3.14)) would fail with a generic "Invalid file" error. Now they display a clear message: "Invalid atom: contains non-ASCII character(s). Atoms must only contain ASCII characters." The fix is implemented at the lexer level, providing consistent error handling across all s-expression parsing. (#12844, fixes #12836, @benodiwal)

• Pass private modules with -H when this is available (#12666, @rgrinberg)

• Allow multiple modules in (modules_flags ...), in coq.theory (#12733, @rlepigre)

• Improve error message for invalid version formats in both (lang dune ...) and (using extension ...) declarations. Changes "Atom of the form NNN.NNN expected" to "Invalid version. Version must be two numbers separated by a dot." (#12833, @benodiwal)

• Fix crash when running dune build @check on a library with virtual modules. (#12644, fixes #12636, @Alizter)

• Provide a more informative error message when (pkg enabled) is put in dune-project instead of dune-workspace. (#12802, fixes #12801, @benodiwal)

• Improve error message when invalid version strings are used in dune-project files. Non-ASCII characters and malformed versions now show a helpful hint with an example of the correct format. (#12794, fixes #12751, @benodiwal)

• Stop hiding the root_module from the include path (#12239, @rgrinberg)

• Allow $ dune init to work on absolute paths (#12601, fixes #7806, @rgrinberg)

• (include_subdirs qualified): Add missing alias dependency to module group. (#12530, @anmonteiro)

• Add Melange compilation to the @all alias in libraries (#12628, @anmonteiro)

• Fix greedy version location in lang declarations. Previously, error locations for invalid lang versions would span multiple bytes for multi-byte UTF-8 characters, causing carets to appear misaligned and seemingly include the closing parenthesis. Now, error locations for ASCII strings show the full length (e.g., "Ali" shows ^^^), while non-ASCII strings show only the first byte (e.g., "è" shows ^) to avoid multi-byte character display issues. (#12869, fixes #12806, @benodiwal)

• melange support: don't emit empty JavaScript modules for generated module aliases. (#12464, @anmonteiro)

Added

• (Experimental): Introduce the library_parameter stanza. It allows users to declare a parameter when using the OxCaml compiler. (#11963, implements #12084, @maiste)
• Added the ability to scroll horizontally in TUI. (#12386, @Alizter)
• Feature: Include shell command that was executed when a cram test has occurred in the error message (#12307, @rgrinberg)
• support expanding variables in (promote (into ..)) (#12832, fixes #12742, @anmonteiro)
• Add support for %{cmt:...} and %{cmti:...} variables to reference compiled annotation files (.cmt and .cmti) containing typed abstract syntax trees with location and type information. (#12634, grants #12633, @Alizter)
• Add $ dune describe tests to describe the tests in the workspace (@Gromototo, #12545, fixes #12030)
• Add argv, the process environment, and the dune version to the config event in the trace (#12909, @rgrinberg)
• Allow dune runtest to properly run while a watch mode server is running. (#12473, grants #8114, @gridbugs and @ElectreAAS)
• Use copy-on-write (COW) when copying files on filesystems that support it (Btrfs, ZFS, XFS, etc), under Linux. (#12074, fixes #12071, @nojb)
• Add support for Tangled ATproto-based code repositories (#12197, @avsm)
• Add support for instantiating OxCaml parameterised libraries. (#12561, @art-w)
• Add a (conflict_markers error|ignore) option to the cram stanza. When (conflict_markers error) is set, the cram test will fail in the presence of conflict markers. Git, diff3 and jujutsu conflict markers are detected. (#12538, #12617, #12655, fixes #12512, @rgrinberg, @Alizter)
• Introduce a %{ppx:lib1+..+libn} stanza to make it possible to refer to ppx executables built by dune. This is useful for writing tests (#12711, @rgrinberg)
• Introduce a (dir ..) field on packages defined in the dune-project. This field allows to associate a directory with a particular package. This makes dune automatically filter out all stanzas in this directory and its descendants with --only-packages. All users are recommended to switch to using this field. (#12614, fixes #3255, @rgrinberg)
• Add support for DUNE_ROOT environment variable, similar to the existing --root CLI parameter. (fixes #12399 @sir4ur0n)
• Introduce an unused-libs alias to detect unused libraries. (#12623, fixes #650, @rgrinberg)
• Add --files flag to dune describe opam-files to print only the names of the opam files line by line. (#9793, @reynir and @Alizter)
• dune exec now accepts absolute paths inside the workspace. (#12094, @Alizter)
• Add coqdoc_header and coqdoc_footer fields to the coq field of the env stanza, and to the coq.theory stanza, allowing to configure a custom header or footer respectively in the HTML output of coqdoc. (#11131, @rlepigre)
• Allow dune fmt to properly run while a watch mode server is running. Note that the --preview flag is not supported in this mode. (#12064, @ElectreAAS)
• Support for generating _CoqProject files for coq.theory stanzas. (#11752, @rlepigre)
• Added (files) stanza, similar to (dirs) to control which files are visible to Dune on a per-directory basis. (#12879, @nojb)
• Add support for %{ocaml-config:ox} (#12236, @jonludlam)
• Introduce dune promotion show command to display the contents of corrected files that are ready for promotion. This allows users to preview changes before running dune promote. The command accepts file arguments to show specific files, or displays all promotable files when called without arguments. (#12669, fixes #3883, @MixiMaxiMouse)
• New (lang rocq) build mode for Rocq 9.0 and later. This new mode is very similar to the existing (lang coq), except that it doesn't need the coq* compatibility wrappers. As of today (lang rocq) doesn't support yet composed builds with Rocq itself, this will be added later. (lang coq) is deprecated, development is frozen, and will be removed at some point in the future. (#12035, @ejgallego, @lysxia, fixes #11572)

Changed

• Don't run ocamldep to compute false dependencies on the root_module (#12227, @rgrinberg)
• dune format-dune-file now uses the syntax version of the Dune project that contains the file being formatted (if any) instead of using the latest version available, which remains the default if there is no Dune project in scope. (#11865, @nojb)
• Persistent DB and process events have been slightly modified. Persistent DB events have more concise names and job events always include full information. (#12867, @rgrinberg)
• Removed the --trace-extended flag. Its functionality is always enabled when tracing is active (#12908, @rgrinberg)
• The test/dune file generated by dune init proj now depends on the project library. (#12791, @shonfeder)
• Starting with version 3.21 of the Dune language, Dune no longer changes the default set of compiler warnings. For users that would like to keep the old behaviour, the variable %{dune-warnings} can be used in an (env) stanza in a top-level Dune file: (env (dev (flags :standard %{dune-warnings}))). (#12766, @nojb)
• Fix: stop generating cmt files for cinaps binaries (#12530, @rgrinberg)

Fixed

• Fix jsoo separate compilation with modules_without_implementation. Regression introduced in #10767. (#12320, fixes #12306 @hhugo)

• Fix runtest-js mistakenly using wrong dependencies (#12324, @vouillon)

• Remove empty .cram.test.t directory during the running of a cram test. (#12329, fixes #12321, @Alizter)

• Fix Cygwin bootstrap (#12325, fixes #12316, @Alizter)

Fixed

• Fix runtest-js mistakenly depending on byte (fixes #12243, #12242, @vouillon and @Alizter)

• Fix the interpretation of paths in dune runtest when running from within a subdirectory. (#12251, fixes #12250, @Alizter)

Changed

• Revert formatting change introduced in 3.20.0 making long lists in s-expressions fill the line instead of formatting them in a vertical way (#12245, reverts #10892, @nojb)

Fixed

• Stop re-running cram tests after promotion when it's not necessary (#11994, @rgrinberg)

• fix: $ dune subst should not fail when adding the version field in opam files (#11801, fixes #11045, @btjorge)

• Kill all processes in the process group after the main process has terminated; in particular this avoids background processes in cram tests to stick around after the test finished (#11841, fixes #11820, @Alizter, @Leonidas-from-XIV)

Added

• (tests) stanzas now generate aliases with the test name. To run (test (name a)) you can do dune build @runtest-a. (#11558, grants part of #10239, @Alizter)

• Inline test libraries now produce aliases runtest-name_of_lib allowing users to run specific inline tests as dune build @runtest-name_of_lib. (#11109, partially fixes #10239, @Alizter)

• feature: $ dune subst use version from dune-project when no version control repository has been detected (#11801, @btjorge)

• Allow dune exec to run concurrently with another instance of dune in watch mode (#11840, @gridbugs)

• Introduce %{os}, %{os_version}, %{os_distribution}, and %{os_family} percent forms. These have the same values as their opam counterparts. (#11863, @rgrinberg)

• Introduce option (implicit_transitive_deps false-if-hidden-includes-supported) that is equivalent to (implicit_transitive_deps false) when -H is supported by the compiler (OCaml >= 5.2) and equivalent to (implicit_transitive_deps true) otherwise. (#11866, fixes #11212, @nojb)

• Add dune describe location for printing the path to the executable that would be run (#11905, @gridbugs)

• dune runtest can now understand absolute paths as well as run tests in specific build contexts (#11936, @Alizter).

• Added 'empty' alias which contains no targets. (#11556 #11952 #11955 #11956, grants #4161, @Alizter and @rgrinberg)

• Allow dune promote to properly run while a watch mode server is running (#12010, @ElectreAAS)

• Add --alias and --alias-rec flags as an alternative to the @@ and @ syntax in the command line (#12043, fixes #5775, @rgrinberg)

• Added a (timeout <float>) field to the (cram) stanza to specify per-test time limits. Tests exceeding the timeout are terminated with an error. (#12041, @Alizter)

Changed

• Format long lists in s-expressions to fill the line instead of formatting them in a vertical way (#10892, fixes #10860, @nojb)

• Switch from MD5 to BLAKE3 for digesting targets and rules. BLAKE3 is both more performant and difficult to break than MD5 (#11735, @rgrinberg, @Alizter)

• Print a warning when dune build runs over RPC (#11833, @gridbugs)

• Stop emitting empty module group wrapper .js file in melange.emit (#11987, fixes #11986, @anmonteiro)

Fixed

• Revert changes in dune exec behaviour introduced in 3.19.0. (#11879, fixes #11870, #11867 and #11881, @Alizter)

Fixed

• Fixed a bug that was causing cram tests attached to multiple aliases to be run multiple times. (#11547, @Alizter)

• Fix: pass pkg-config (extra) args in all pkgconfig invocations. A missing --personality flag would result in pkgconf not finding libraries in some contexts. (#11619, @MisterDA)

• Fix: Evaluate enabled_if when computing the stubs for stanzas such as foreign_library (#11707, @Alizter, @rgrinberg)

• Fix $ dune describe pp for libraries in the presence of (include_subdirs unqualified) (#11729, fixes #10999, @rgrinberg)

• Fix $ dune subst in sub directories of a git repository (#11760, fixes #11045, @Richard-Degenne)

• Fix a crash involving Path.drop_prefix when using Melange on Windows (#11767, @nojb)

Added

• Added detection and warning for common typos in package dependency constraints (#11600, fixes #11575, @kemsguy7)

• Added (extra_objects) field to (foreign_library) stanza with (:include) support. (#11683, @Alizter)

Changed

• Allow build RPC messages to be handled by dune's RPC server in eager watch mode (#11622, @gridbugs)

• Allow concurrent build with RPC server (#11712, @gridbugs)

Fixed

• fix compatibility with ocaml.5.4.0 by avoiding shadowing sigwinch (@nojb, #11639)

Fixed

• fix: pass pkg-config (extra) args in all pkgconfig invocations. A missing --personality flag would result in pkgconf not finding libraries in some contexts. (#11619, @MisterDA)

Fixed

• Support HaikuOS: don't call execve since it's not allowed if other pthreads have been created. The fact that Haiku can't call execve from other threads than the principal thread of a process (a team in haiku jargon), is a discrepancy to POSIX and hence there is a bug about it. (@Sylvain78, #10953)

• Fix flag ordering in generated Merlin configurations (#11503, @voodoos, fixes ocaml/merlin#1900, reported by @vouillon)

Added

• Add (format-dune-file <src> <dst>) action. It provides a replacement to dune format-dune-file command. (#11166, @nojb)

• Allow the --prefix flag when configuring dune with ocaml configure.ml. This allows to set the prefix just like $ dune install --prefix. (#11172, @rgrinberg)

• Allow arguments starting with + in preprocessing definitions (starting with (lang dune 3.18)). (@amonteiro, #11234)

• Support for opam (maintenance_intent ...) in dune-project (#11274, @art-w)

• Validate opam maintenance_intent (#11308, @art-w)

• Support not in package dependencies constraints (#11404, @art-w, reported by @hannesm)

Changed

• Warn when failing to discover root due to reads failing. The previous behavior was to abort. (@KoviRobi, #11173)

• Use shorter path for inline-tests artifacts. (@hhugo, #11307)

• Allow dash in dune init project name (#11402, @art-w, reported by @saroupille)

• On Windows, under heavy load, file delete operations can sometimes fail due to AV programs, etc. Guard against it by retrying the operation up to 30x with a 1s waiting gap (#11437, fixes #11425, @MSoegtropIMC)

• Cache: we now only store the executable permission bit for files (#11541, fixes #11533, @ElectreAAS)

• Display negative error codes on Windows in hex which is the more customary way to display NTSTATUS codes (#11504, @MisterDA)

Fixed

• Fix a crash in the Melange rules that would prevent compiling public library implementations of virtual libraries. (@anmonteiro, #11248)
• Pass melange.emit's compile_flags to the JS emission phase. (@anmonteiro, #11252)
• Disallow private implementations of public virtual libs in melange mode. (@anmonteiro, #11253)
• Wasm_of_ocaml: fix the execution of tests in a sandbox. (#11304, @vouillon)

Fixed

• When a library declares (no_dynlink), then the .cmxs file for it is no longer built. (#11176, @nojb)

• Fix bug that could result in corrupted file copies by Dune, for example when using the copy_files# stanza or the copy# action. (@nojb, #11194, fixes #11193)

• Remove useless error message when running $ dune subst in empty projects. (@rgrinberg, #11204, fixes #11200)

Fixed

• Show the context name for errors happening in non-default contexts. (#10414, fixes #10378, @jchavarri)

• Correctly declare dependencies of indexes so that they are rebuilt when needed. (#10623, @voodoos)

• Don't depend on coq-stdlib being installed when expanding variables of the coq.version family (#10631, fixes #10629, @gares)

• Error out if no files are found when using copy_files. (#10649, @jchavarri)

• Re_export dune-section private library in the dune-site library stanza, in order to avoid failure when generating and building sites modules with implicit_transitive_deps = false. (#10650, fixes #9661, @MA0100)

• Expect test fixes: support multiple modes and fix dependencies when there is a custom runner (#10671, @vouillon)

• In a (library) stanza with (extra_objects) and (foreign_stubs), avoid double linking the extra object files in the final executable. (#10783, fixes #10785, @nojb)

• Map (re_export) library dependencies to the exports field in META files, and vice-versa. This field was proposed in to https://discuss.ocaml.org/t/proposal-a-new-exports-field-in-findlib-meta-files/13947. The field is included in Dune-generated META files only when the Dune lang version is >= 3.17. (#10831, fixes #10830, @nojb)

• Fix staged pps preprocessors on Windows (which were not working at all previously) (#10869, fixes #10867, @nojb)

• Fix dune describe when an executable is disabled with enabled_if. (#10881, fixes #10779, @moyodiallo)

• Fix an issue where C stubs would be rebuilt whenever the stderr of Dune was redirected. (#10883, fixes #10882, @nojb)

• Fix the URL opened by the command dune ocaml doc. (#10897, @gridbugs)

• Fix the file referred to in the error/warning message displayed due to the dune configuration version not supporting a particular configuration stanza in use. (#10923, @H-ANSEN)

• Fix enabled_if when it uses env variable. (#10936, fixes #10905, @moyodiallo)

• Fix exec -w for relative paths with --root argument (#10982, @gridbugs)

• Do not ignore the (locks ..) field in the test and tests stanza (#11081, @rgrinberg)

• Tolerate files without extension when generating merlin rules. (#11128, @anmonteiro)

Added

• Make Merlin/OCaml-LSP aware of "hidden" dependencies used by (implicit_transitive_deps false) via the -H compiler flag. (#10535, @voodoos)

• Add support for the -H flag (introduced in OCaml compiler 5.2) in dune (requires lang versions 3.17). This adaptation gives the correct semantics for (implicit_transitive_deps false). (#10644, fixes #9333, ocsigen/tyxml#274, #2733, #4963, @MA0100)

• Add support for specifying Gitlab organization repositories in source stanzas (#10766, fixes #6723, @H-ANSEN)

• New option to control jsoo sourcemap generation in env and executable stanza (#10777, fixes #10673, @hhugo)

• One can now control jsoo compilation_mode inside an executable stanza (#10777, fixes #10673, @hhugo)

• Add support for specifying default values of the authors, maintainers, and license stanzas of the dune-project file via the dune config file. Default values are set using the (project_defaults) stanza (#10835, @H-ANSEN)

• Add names to source tree events in performance traces (#10884, @jchavarri)

• Add codeberg as an option for defining project sources in dune-project files. For example, (source (codeberg user/repo)). (#10904, @nlordell)

• dune runtest can now run individual tests with dune runtest mytest.t (#11041, @Alizter).

• Wasm_of_ocaml support (#11093, @vouillon)

• Add a coqdep_flags field to the coq field of the env stanza, and to the coq.theory stanza, allowing to configure coqdep flags. (#11094, @rlepigre)

Changed

• Remove all remnants of the experimental patch-back-source-tree. (#10771, @rgrinberg)

• Change the preset value for author and maintainer fields in the dune-project file to encourage including emails. (#10848, @punchagan)

• Tweak the preset value for tags in the dune-project file to hint at topics not having a special meaning. (#10849, @punchagan)

• Change some colors to improve readability in light-mode terminals (#10890, @gridbugs)

• Forward the linkall flag to jsoo in whole program compilation as well (#10935, @hhugo)

• Configurator uses pkgconf as pkg-config implementation when available and forwards it the target of ocamlc -config. (#10937, @pirbo)

• Enable Dune cache by default. Add a new Dune cache setting enabled-except-user-rules, which enables the Dune cache, but excludes user-written rules from it. This is a conservative choice that can avoid breaking rules whose dependencies are not correctly specified. This is the current default. (#10944, #10710, @nojb, @ElectreAAS)

• Do not add dune dependency in dune-project when creating projects with dune init proj. The Dune dependency is implicitely added when generating opam files (#11129, @Leonidas-from-XIV)

Fixed

• Call the C++ compiler with -std=gnu++11 when using OCaml >= 5.0 (#10962, @kit-ty-kate)

  Added

Added

• Allow libraries with the same (name ..) in projects as long as they don't conflict during resolution (via enabled_if). (#10307, @anmonteiro, @jchavarri)

• dune describe pp now finds the exact module and the stanza it belongs to, instead of guessing the name of the preprocessed file. (#10321, @anmonteiro)

• Print the result of dune describe pp with the respective dialect printer. (#10322, @anmonteiro)

• Add new flag --context to dune ocaml-merlin, which allows to select a Dune context when requesting Merlin config. Add dune describe contexts subcommand. Introduce a field generate_merlin_rules for contexts declared in the workspace, that allows to optionally produce Merlin rules for other contexts besides the one selected for Merlin (#10324, @jchavarri)

• Melange: add include paths for private library .cmj files during JS emission. (#10416, @anmonteiro)

• dune ocaml-merlin: communicate additional directives SOURCE_ROOT, UNIT_NAME (the actual name with wrapping) and INDEX with the paths to the index(es). (#10422, @voodoos)

• Add a new alias @ocaml-index that uses the ocaml-index binary to generate indexes that can be read by tools such as Merlin to provide project-wide references search. (#10422, @voodoos)

• Merlin: add optional (merlin_reader CMD) construct to (dialect) stanza to configure a Merlin reader (#8567, @andreypopp)

Changed

• Melange: treat private libraries with (package ..) as public libraries, fixing an issue where import paths were wrongly emitted. (#10415, @anmonteiro)

• Install .glob files for Coq theories too (#10602, @ejgallego)

Fixed

• Don't try to document nonexistent libraries in doc-new target (#10319, fixes #10056, @jonludlam)

• Make dune-site's load_all function look for META files so that it doesn't fail on empty directories in the plugin directory (#10458, fixes #10457, @shym)

• Fix incorrect warning for libraries defined inside nonexistant directories using (subdir ..) and used by executables using dune-build-info (#10525, @rgrinberg)

• Don't try to take build lock when running coq top --no-build (#10547, fixes #7671, @lzy0505)

• Make sure to truncate Dune's lock file after locking and unlocking so that users cannot observe incorrect PID's (#10575, @rgrinberg)

• MDX: link MDX binary with byte_complete. This fixes (libraries) with foreign archives on Linux. (#10586, fixes #10582, @anmonteiro)

• Virtual libraries: fix an issue where linking an executable involving several virtual libries would cause an error. (#10581, fixes #10460, @rgrinberg)

Fixed

• Fix interpretation of exists_if predicate in META files of installed libraries containing more than one element. (#10564, fixes #10563, @dbuenzli, @nojb)

• Fix TSAN warning in wait4 stubs (#10554, fixes #10553, @emillon)

Fixed

• If no directory targets are defined, then do not evaluate enabled_if (#10442, @rgrinberg)

• Fix a bug where Coq projects were being rebuilt from scratch each time the dependency graph changed. (#10446, fixes #10149, @alizter)

Added

• Add link flags to to ocamlmklib for ctypes stubs (#8784, @frejsoya)

• Remove some unnecessary limitations in the expansions of percent forms in install stanza. For example, the %{env:..} form can be used to select files to be installed. (#10160, @rgrinberg)

• Allow artifact expansion percent forms (%{cma:..}, %{cmo:..}, etc.) in more contexts. Previously, they would be randomly forbidden in some fields. (#10169, @rgrinberg)

• Allow %{inline_tests} in more contexts (#10191, @rgrinberg)

• Remove limitations on percent forms in the (enabled_if ..) field of libraries (#10250, @rgrinberg)

• Support dialects in dune describe pp (#10283, @emillon)

• Allow defining executables or melange emit stanzas with the same name in the same folder under different contexts. (#10220, @rgrinberg, @jchavarri)

Fixed

• coq: Delay Coq rule setup checks so OCaml-only packages can build in hybrid Coq/OCaml projects when coqc is not present. Thanks to @vzaliva for the test case and report (#9845, fixes #9818, @rgrinberg, @ejgallego)

• Fix conditional source selection with select on bigarray in OCaml 5 (#10011, @moyodiallo)

• melange: fix inconsistency in virtual library implementation. Concrete modules within a virtual library can now refer to its virtual modules too (#10051, fixes #7104, @anmonteiro)

• melange: fix a bug that would cause stale import paths to be emitted when moving source files within (include_subdirs ..) (#10286, fixes #9190, @anmonteiro)

• Dune file formatting: output utf8 if input is correctly encoded (#10113, fixes #9728, @moyodiallo)

• Fix expanding dependencies and locks specified in the cram stanza. Previously, they would be installed in the context of the cram test, rather than the cram stanza itself (#10165, @rgrinberg)

• Fix bug with dune exec --watch where the working directory would always be set to the project root rather than the directory where the command was run (#10262, @gridbugs)

• Regression fix: sign executables that are promoted into the source tree (#10263, fixes #9272, @emillon)

• Fix crash when decoding dune-package for libraries with (include_subdirs qualified) (#10269, fixes #10264, @emillon)

Changed

• Remove the --react-to-insignificant-changes option. (#10083, @rgrinberg)

Fixed

• When a directory is changed to a file, correctly remove it in subsequent dune build runs. (#9327, fix #6575, @emillon)

• Fix a problem with the doc-new target where transitive dependencies were missed during compile. This leads to missing expansions in the output docs. (#9955, @jonludlam)

• coq: fix performance regression in coqdep unescaping (#10115, fixes #10088, @ejgallego, thanks to Dan Christensen for the report)

• coq: memoize coqdep parsing, this will reduce build times for Coq users, in particular for those with many .v files (#10116, @ejgallego, see also #10088)

• on Windows, use an unicode-aware version of CreateProcess to avoid crashes when paths contains non-ascii characters. (#10212, fixes #10180, @emillon)

• fix compilation on non-glibc systems due to signal.h not being pulled in spawn stubs. (#10256, @emillon)

Added

• Introduce a (dynamic_include ..) stanza. This is like (include foo) but allows foo to be the target of a rule. Currently, there are some limitations on the stanzas that can be generated. For example, public executables, libraries are currently forbidden. (#9913, @rgrinberg)

• Introduce $ dune promotion list to print the list of available promotions. (#9705, @moyodiallo)

• If Sherlodoc is installed, add a search bar in generated HTML docs (#9772, @EmileTrotignon)

• Add only_sources field to copy_files stanza (#9827, fixes #9709, @jchavarri)

• The (foreign_library) stanza now supports the (enabled_if) field. (#9914, @nojb)

Fixed

• Fix $ dune install -p incorrectly recognizing packages that are supposed to be filtered (#9879, fixes #4814, @rgrinberg)

• subst: correctly handle opam files in opam/ subdirectory (#9895, fixes #9862, @emillon)

• Odoc private rules are not set up if a library is not available due to enabled_if (#9897, @rgrinberg and @jchavarri)

Changed

• When dune language 3.14 is enabled, resolve the binary in (run %{bin:..} ..) from where the binary is built. (#9708, @rgrinberg)

• boot: remove single-command bootstrap. This was an alternative bootstrap strategy that was used in certain conditions. Removal makes the bootstrap a bit slower on Linux when only a single core is available, but bootstrap is now reproducible in all cases. (#9735, fixes #9507, @emillon)

• Fix performance regression for incremental builds (#9769, fixes #9738, @rgrinberg)

• Fix dune ocaml top-module to correctly handle absolute paths. (#8249, fixes #7370, @Alizter)

• subst: ignore broken symlinks when looking at source files (#9810, fixes #9593, @emillon)

• subst: do not fail on 32-bit systems when large files are encountered. Just log a warning in this case. (#9811, fixes #9538, @emillon)

• boot: sort directory entries in readdir. This makes the dune binary reproducible in terms of filesystem order. (#9861, fixes #9794, @emillon)

Added

• Add command dune cache clear to completely delete all traces of the Dune cache. (#8975, @nojb)

• Allow to disable Coq 0.8 deprecation warning (#9439, @ejgallego)

• Allow OCAMLFIND_TOOLCHAIN to be set per context in the workspace file through the env stanza. (#9449, @rgrinberg)

• Menhir: generate .conflicts file by default. Add new field to the (menhir) stanza to control the generation of this file: (explain <blang expression>). Introduce (menhir (flags ...) (explain ...)) field in the (env) stanza, delete (menhir_flags) field. All changes are guarded under a new version of the Menhir extension, 3.0. (#9512, @nojb)

• Directory targets can now be cached. (#9535, @rleshchinskiy)

• It is now possible to use special forms such as (:include) and variables %{read-lines:} in (modules) and similar fields. Note that the dependencies introduced in this way (i.e., the files being read) must live in a different directory than the stanza making use of them. (#9578, @nojb)

• Remove warning 30 from default set for projects where dune lang is at least 3.13 (#9568, @gasche)

• Add coqdoc_flags field to coq field of env stanza, allowing the setting of workspace-wide defaults for coqdoc_flags. (#9280, fixes #9139, @Alizter)

• ctypes: fix an error where (ctypes) with no (function_description) would cause an error trying refer to a nonexistent _stubs.a dependency (#9302, fix #9300, @emillon)

Changed

• Check that package names in (depends) and related fields in dune-project are well-formed. (#9472, fixes #9270, @ElectreAAS)

Fixed

• Do not ignore (formatting ..) settings in context or workspace files (#8447, @rgrinberg)

• Fixed a bug where Dune was incorrectly parsing the output of coqdep when it was escaped, as is the case on Windows. (#9231, fixes #9218, @Alizter)

• Copying mode for sandboxes will now follow symbolic links (#9282, @rgrinberg)

• Forbid the empty (binaries ..) field in the env stanza in the workspace file unless language version is at least 3.2. (#9309, @rgrinberg)

• [Coq] Fix bug in computation of flags when composed with boot theories. (#9347, fixes #7909, @ejgallego)

• Fixed a bug where the (select) field of the (libraries) field of the (test) stanza wasn't working properly. (#9387, fixes #9365, @Alizter)

• Fix handling of the PATH argument to dune init proj NAME PATH. An intermediate directory called NAME is no longer created if PATH is supplied, so dune init proj my_project . will now initialize a project in the current working directory. (#9447, fixes #9209, @shonfeder)

• Experimental doc rules: Correctly handle the case when a package depends upon its own sublibraries (#9461, fixes #9456, @jonludlam)

• Resolve various public binaries to their build location, rather than to where they're copied in the _build/install directory (#9496, fixes #7908, @rgrinberg).

• Correctly ignore warning flags in vendored projects (#9515, @rgrinberg)

• Use watch exclusions in watch mode on MacOS (#9643, fixes #9517, @PoorlyDefinedBehaviour)

• Fix Merlin configuration for (include_subdirs qualified) modules (#9659, fixes #8297, @rgrinberg)

• Fix handling of enabled_if in binary install stanzas. Previously, we'd ignore the result of enabled_if when evaluating %{bin:..} (#9707, @rgrinberg)

Fixed

• Fix version check in runtest_alias for cram stanza (#9454, @emillon)

• Fix stack overflow when a (run) action can not be parsed. (#9530, fixes #9529, @gridbugs)

Added

• Introduce $ dune ocaml doc to open and browse documentation. (#7262, fixes #6831, @EmileTrotignon)

• dune cache trim now accepts binary byte units: KiB, MiB, etc. (#8618, @Alizter)

• Introduce the runtest_alias field to the cram stanza. This allows removing default runtest alias from tests. (@rgrinberg, #8887)

• Display cache location in Dune log (#8974, @nojb)

• Dune can now be built and installed on Haiku (#8795, fix #8551, @Alizter)

• Mark installed directories in dune-package files. This fixes (package) dependencies against packages that contain such directories. (#8953, fixes #8915, @emillon)

• Introduce new experimental odoc rules (#8803, @jonjudlam)

Changed

• dune-build-info: when version="" is found in a META file, we now return None as a version string (#9177, @emillon)

• No longer force colors for OCaml 4.03 and 4.04 (#8778, @rgrinberg)

• Dependencies in the copying sandbox are now writeable (#8920, @rgrinberg)

• Rules that only use internal dune actions (write-file, echo, etc.) can now be sandboxed. (#9041, fixes #8854, @rgrinberg)

• Add test_ prefix to default test name in dune init project (#9257, fixes #9131, @9sako6)

Fixed

• Do not ignore libraries named bigarray when they are defined in conjunction with OCaml 5.0 (#8902, fixes #8901, @rgrinberg)

• Correctly ignore bigarray on recent versions of OCaml (#9076, @rgrinberg)

• Absent packages shouldn't prevent all rules from being loaded (#8948, fixes #8630, @rgrinberg)

• Correctly determine the stanza of menhir modules when (include_subdirs qualified) is enabled (@rgrinberg, #8949, fixes #7610)

• Re-run actions whenever (expand_aliases_in_sandbox) changes (#8990, @rgrinberg)

• Do not re-run rules when their location changes (#9052, @rgrinberg)

• [coq rules] Be more tolerant when coqc --print-version / --config don't work properly, and fallback to a reasonable default. This fixes problems when building Coq projects with (stdlib no) and likely other cases. (#8966, fix #8958, @Alizter, reported by Lasse Blaauwbroek)

• Dune will now run at a lower framerate of 15 fps rather than 60 when INSIDE_EMACS. (#8812, @Alizter)

Fixed

• Fix dune rpc commands on Windows (#8806, fixes #8799, @nojb)

• Fix inline_tests when the partition list is empty (#8849, fixes #8848, @hhugo)

Added

• enabled_if now supports arch_sixtyfour variable (#8023, fixes #7997, @Alizter)

• Experimental: Added a $ dune monitor command that can connect to a running dune build in watch mode and display the errors and progress. (#8152, @Alizter)

• The progress RPC procedure now has an extra field for the In_progress constructor for the number of failed jobs. (#8212, @Alizter)

• Add a --preview flag to dune fmt which causes it to print out the changes it would make without applying them (#8289, @gridbugs)

• Introduce (source_trees ..) to the install stanza to allow installing entire source trees. (#8349, @rgrinberg)

• Add --stop-on-first-error option to dune build which will terminate the build when the first error is encountered. (#8400, @pmwhite and @Alizter)

• Dune now displays the number of errors when waiting for changes in watch mode. (#8408, fixes #6889, @Alizter)

• Add with_prefix keyword for changing the prefix of the destination of installed files matched by globs. (#8416, @gridbugs)

• Added experimental --display tui option for Dune that opens an interactive Terminal User Interface (TUI) when Dune is running. Press '?' to open up a help screen when running for more information. (#8429, @Alizter and @rgrinberg)

• Add a warnings field to dune-project files as a unified mechanism to enable or disable dune warnings (@rgrinberg, 8448)

• dune exec: support syntax like %{bin:program}. This can appear anywhere in the command line, so things like dune exec time %{bin:program} now work. (#6035, #8474, fixes #2691, @emillon, @Leonidas-from-XIV)

• Add a new alias @doc-json to build odoc documentation in JSON format. This output can be consumed by external tools. (#8178, @emillon)

Changed and Fixed

• Use posix_spawn instead of fork on MacOS. This gives us a performance boost and allows us to re-enable thread. (#8090, @rgrinberg)

• Modules that were declared in (modules_without_implementation), (private_modules) or (virtual_modules) but not declared in (modules) will raise an error. (#7674, @Alizter)

• No longer emit linkopts(javascript) in META files (#8168, @hhugo)

• RPC message styles are now serialised meaning that RPC diagnostics keep their ANSI styling. (#8516, fixes #6921, @Alizter)

• Truncate output from actions that produce too much output (@tov, #8351)

• Allow libraries to shadow OCaml built-in libraries. Previously, built-in libraries would always take precedence. (@rgrinberg, #8558)

• dune utop no longer links utop in "custom" mode, which should make this command considerably faster. (#8631, fixes #6894, @nojb)

• Ensure that package names in dune-project are valid opam package names. (#8331, @emillon)

• init: check that module names are valid (#8644, fixes #8252, @emillon)

• dune init: parse --public as a public name (#8603, fixes #7108, @emillon)

• Stop signing source files with substitutions. Sign only binaries instead (#8361, fixes #8360, @anmonteiro)

• Make copy sandbox support directory targets. (#8705, fixes #7724, @emillon)

Deprecated and Removed

• Deprecate install destination paths beginning with ".." to prevent packages escaping their designated installation directories. (#8350, @gridbugs)

• Remove warning against .dune files generated by pre Dune 2.0 (#8611, @rgrinberg)

• Remove versions 0.1 and 0.2 of the experimental ctypes extension. (#8293, @emillon)

Fixes

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

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)

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)

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)

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)

• 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)

• 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)

• 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)

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)

• Fix segfault on MacOS when dune was being shutdown while in watch mode. (#7312, fixes #6151, @gridbugs, @emillon)

• Fix preludes not being recorded as dependencies in the (mdx) stanza (#7109, fixes #7077, @emillon).

• Pass correct flags when compiling stdlib.ml. (#7241, @emillon)

• Handle "Too many links" errors when using Dune cache on Windows. The fix in 3.7.0 for this same issue was not effective due to a typo. (#7472, @nojb)

dune executable

Added

• Allow running $ dune exec in watch mode (with the -w flag). In watch mode, $ dune exec the executed binary whenever it is recompiled. (#6966, @gridbugs)

• Add a dune cache size command for displaying the size of the cache (#6638, @Alizter)

• Allow $ dune ocaml dump-dot-merlin to run in watch mode. Also this command shouldn't print "Entering Directory" mesages. (#6497, @rgrinberg)

• Add native support for polling mode on Windows (#7010, @yams-yams, @nojb, review by @Rucikir and @jbeckford)

• Auto-detect dune-workspace files as dune files in Emacs (#7061, @ilankri)

• Allow $ dune utop to load libraries defined in data only directories defined using (subdir ..) (#6631, @rgrinberg)

Changed

• Make dune describe workspace return consistent dependencies for executables and for libraries. By default, compile-time dependencies towards PPX-rewriters are from now not taken into account (but runtime dependencies always are). Compile-time dependencies towards PPX-rewriters can be taken into account by providing the --with-pps flag. (#6727, fixes #6486, @esope)

• Use colored output with MDX when Dune colors are enabled. (#6462, @MisterDA)

• Use colored output with GCC and Clang when compiling C stubs. The flag -fdiagnostics-color=always is added to the :standard set of flags. (#4083, @MisterDA)

• Move $ dune ocaml-merlin -dump-config=$dir to $ dune ocaml merlin dump-config $dir. (#6547, @rgrinberg)

Fixed

• Fix parsing of OCaml errors that contain code excerpts with ... in them. (#7008, @rgrinberg)

• Fix --trace-file output. Dune now emits a single complete event for every executed process. Unterminated async events are no longer written. (#6892, @rgrinberg)

• Print missing newline after $ dune exec. (#6821, fixes #6700, @rgrinberg, @Alizter)

• Fix binary corruption when installing or promoting in parallel (#6669, fixes #6668, @edwintorok)

• Report an error if dune init ... would create a "dune" file in a location which already contains a "dune" directory (#6705, @gridbugs)

• Fix the parsing of alerts. They will now show up in diagnostics correctly. (#6678, @rginberg)

• Print "Leaving Directory" whenever "Entering Directory" is printed. (#6419, fixes #138, @cpitclaudel, @rgrinberg)

• Remove "Entering Directory" messages for $ dune install. (#6513, @rgrinberg)

• dune clean should no longer fail under Windows due to the inability to remove the .lock file. Also, bring the implementation of the global lock under Windows closer to that of Unix. (#6523, @nojb)

• Fix missing dependencies when detecting the kind of C compiler we're using (#6610, fixes #6415, @emillon)

• Remove spurious build dir created when running dune init proj ... (#6707, fixes #5429, @gridbugs)

• Validate the command line arguments for $ dune ocaml top-module. This command requires one positional argument (#6796, fixes #6793, @rgrinberg)

• Fix dependency cycle when installing files to the bin section with glob_files (#6764, fixes #6708, @gridbugs)

• Handle "Too many links" errors when using Dune cache on Windows (#6993, @nojb)

• Pre-emptively clear screen in watch mode (#6987, fixes #6884, @rgrinberg)

• Allow --sandbox to affect ocamldep invocations. Previously, they were wrongly marked as incompatible (#6749, @rgrinberg)

dune language

Added

• Allow (include_subdirs qualified) for OCaml projects. (#6594, fixes #1084, @rgrinberg)

• Format dune files when they are named dune-file. This occurs when we enable the alternative file names project option. (#6566, @rgrinberg)

• Add map_workspace_root dune-project stanza to allow disabling of mapping of workspace root to /workspace_root. (#6988, fixes #6929, @richardlford)

• Allow the cinaps stanza to set a custom alias. By default, if the alias is not set then the cinaps actions will be attached to both @cinaps and @runtest (#6991, @rgrinberg)

• Add (using ctypes 0.3). When used, paths in (ctypes) are interpreted relative to where the stanza is defined. (#6883, fixes #5325, @emillon)

Changed

• Stop passing -q flag in dune coq top, which allows for .coqrc to be loaded. (#6848, fixes #6847, @Alizter)

• Coq native mode is now automatically detected by Dune starting with Coq lang 0.7. (mode native) has been deprecated in favour of detection from the configuration of Coq. (#6409, @Alizter)

• Accurately determine merlin configuration for all sources selected with copy# and copy_files#. The old heuristic of looking for a module in parent directories is removed (#6594, @rgrinberg)

Fixed

• Fix parsing of the <= operator in blang expressions of dune files. Previously, the operator would be interpreted as <. (#6928, @tatchi)

• Fix preprocessing with staged_pps (#6748, fixes #6644, @rgrinberg)

• Fix the parsing of decimal and hexadecimal escape literals in dune, dune-package, and other dune s-expression based files (#6710, @shym)

• Fix cross compilation configuration when a context with targets is itself a host of another context (#6958, fixes #6843, @rgrinberg)

• Allow compilation rules to be impacted by (env ..) stanzas that modify the environment or set binaries. (#6527, @rgrinberg)

• Fix handling of support files generated by odoc. (#6913, @jonludlam)

• Fix the compilation of modules generated at link time when implicit_transitive_deps is enabled (#6642, @rgrinberg)

• Fix inline tests with js_of_ocaml and whole program compilation mode enabled (#6645, @hhugo)

• Fix js_of_ocaml separate compilation rules when --enable=effects ,--enable=use-js-string or --toplevel is used. (#6714, #6828, #6920, @hhugo)

• Fix js_of_ocaml separate compilation in presence of linkall (#6832, #6916, @hhugo)

• coqdep is now called once per theory, instead of one time per Coq file. This should significantly speed up some builds, as coqdep startup time is often heavy (#7048, @Alizter, @ejgallego)

• Fix configurator when using the MSVC compiler (#6538, fixes #6537, @nojb)

• Fix running the RPC server on windows (#6721 fixes #6720, @rgrinberg)

• Fix status line enabled when ANSI colors are forced. (#6503, @MisterDA)

• Fix build with MSVC compiler (#6517, @nojb)

• Do not shadow library interface modules (#6549, fixes #6545, @rgrinberg)

dune executable

This lists features of the “dune” executable itself. Upgrading dune will bring in these changes. We consider these changes safe, but it is difficult to define what a breaking change is for a command-line tool (for example, some error messages change). It is important to note that just upgrading the dune executable is not supposed to change how dune interprets existing projects. If just upgrading dune breaks compilation, it is a bug in dune, please report it!

Added

• Introduce a $ dune ocaml top-module subcommand to load modules directly without sealing them behind the signature. (#5940, @rgrinberg)
• Revive $ dune external-lib-deps under $ dune describe external-lib-deps. (#6045, @moyodiallo)
• Extend the promotion CLI to a dune promotion group: dune promote is moved to dune promotion apply (the former still works) and the new dune promotion diff command can be used to just display the promotion without applying it. (#6160, fixes #5368, @emillon)
• Build progress status now shows number of failed jobs (#6242, @Alizter)
• Allow promoting into source directories specified by subdir (#6404, fixes #3502, @rgrinberg)
• Support CLICOLOR and CLICOLOR_FORCE to enable/disable/force ANSI colors. (#6340, fixes #6323, @MisterDA).
• Create a fake socket file _build/.rpc/dune on windows to allow rpc clients to connect using the build directory. (#6329, @rgrinberg)

Fixed

• Forbid multiple instances of dune running concurrently in the same workspace. (#6360, fixes #236, @rgrinberg)
• Make dune describe workspace return the correct root path (#6380, fixes #6379, @esope)
• Fix running inline tests in bytecode mode (#5622, fixes #5515, @dariusf)

(lang dune 3.6)

This lists changes if you opt into the new (lang dune 3.6) version in your dune-project file. For this too, these are changes that we consider safe, but they can require changes to your dune files. For example, sandboxing is enabled in more places, which means that you might have to be more precise in expressing your dependencies. Please reach out on the issue tracker if you have trouble fixing your dune file or if something does not seem to be possible anymore.

Added

• Add (glob_files <glob>) and (glob_files_rec <glob>) terms to the files field of the install stanza (#6250, closes #6018, @gridbugs)
• Allow Byte_complete binaries to be installable (#4837, @AltGr, @rgrinberg)
• Allow :standard in the (modules) field of the coq.pp stanza (#6229, fixes #2414, @Alizter)

Fixed

• Allow absolute build directories to find public executables. For example, those specified with (deps %{bin:...}) (#6326, @anmonteiro)
• [ctypes] do not mangle user written names in the ctypes stanza (#6374, fixes #5561, @rgrinberg)
• Forbid private libraries with (package ..) set from depending on private libraries that don't belong to a package (#6385, fixes #6153, @rgrinberg)
• [ctypes] always re-run pkg-config because we aren't tracking its external dependencies (#6052, @rgrinberg)
• [ctypes] remove dependency on configurator in the generated rules (#6052, @rgrinberg)
• Fix passing of flags to dune coq top (#6369, fixes #6366, @Alizter)
• Prevent crash if absolute paths are used in the install stanza and in recursive globs. These cases now result in a user error. (#6331, @gridbugs)

dune executable

This lists features of the "dune" executable itself. Upgrading dune will bring in these changes. We consider these changes safe, but it is difficult to define what a breaking change is for a command-line tool (for example, some error messages change). It is important to note that just upgrading the dune executable is not supposed to change how dune interprets existing projects. If just upgrading dune breaks compilation, it is a bug in dune, please report it!

Added

• Allow dune describe workspace to accept directories as arguments. The provided directories restrict the worskpace description to those directories. (#6107, fixes #3893, @esope)
• Add a terminal persistence mode that attempts to clear the terminal history. It is enabled by setting terminal persistence to clear-on-rebuild-and-flush-history (#6065, @rgrinberg)

Fixed

• Fix build-info version when used with flambda (#6089, fixes #6075, @jberdine)
• Fix compilation of Dune under esy on Windows (#6109, fixes #6098, @nojb)
• Improve error message when parsing several licenses in (license) (#6114, fixes #6103, @emillon)
• Handle CSI n K code in ANSI escape codes from commands. (#6214, fixes #5528, @emillon)
• Do not ignore rules marked (promote (until-clean)) when --ignore-promoted-rules (or -p) is passed. (#6010, fixes #4401, @emillon)

Changed

• dune install: copy files in an atomic way (#6150, @emillon)
• update vendored copy of cmdliner to 1.1.1. This improves the built-in documentation for command groups such as dune ocaml. (#6038, @emillon, #6169, @shonfeder)
• Extend dune describe to include the root path of the workspace and the relative path to the build directory. (#6136, @reubenrowe)

macOS support

This is technically a subset of above section. For M1 mac users, dune 3.5.0 is the first version which will correctly support dune-build-info.

Added

• on macOS, sign executables produced by artifact substitution (#6137, #6231, fixes #5650, fixes #6226, @emillon)
• Enable file watching on MacOS SDK < 10.13. (#6218, @rgrinberg)

Fixed

• macOS: Handle unknown fsevents without crashing (#6217, @rgrinberg)

(lang dune 3.5)

This lists changes if you opt into the new (lang dune 3.5) version in your dune-project file. For this too, these are changes that we consider safe, but they can require changes to your dune files. For example, sandboxing is enabled in more places, which means that you might have to be more precise in expressing your dependencies. Please reach out on the issue tracker if you have trouble fixing your dune file or if something does not seem to be possible anymore.

Added

• Add a runtime_deps field in the cinaps stanza to specify runtime dependencies for running the cinaps preprocessing action (#6175, @rgrinberg)
• Allow rules producing directory targets to be not sandboxed (#6056, @rgrinberg)
• Introduce a dirs field in the install stanza to install entire directories (#5097, fixes #5059, @rgrinberg)
• Add an (include <file>) term to the include_dirs field for adding directories to the include paths sourced from a file. (#6058, fixes #3993, @gridbugs)
• Support (extra_objects ...) field in (executable ...) and (library ...) stanzas (#6084, fixes #4129, @gridbugs)
• Allow rules producing directory targets to create symlinks (#6077, fixes #5945, @rgrinberg)
• Added an (aliases ...) field to the (rules ...) stanza which allows the specification of multiple aliases per rule (#6194, @Alizter)
• Allow include statement in install stanza (#6139, fixes #256, @gridbugs)
• Add a new experimental feature mode_specific_stubs that allows the specification of different flags and sources for foreign stubs depending on the build mode (#5649, @voodoos)

Changed

• Sandbox running cinaps actions starting from cinaps 1.1 (#6176, @rgrinberg)
• Cinaps actions are now sandboxed by default (#6062, @rgrinberg)
• Menhir rules are now sandboxed by default (#6076, @rgrinberg)
• Inline tests are now sandboxed by default (#6079, @rgrinberg)

Fixed

• Shadow alias module Foo__ when building a library Foo (#6126, @rgrinberg)
• Disallow generating targets in sub direcories in inferred rules. The check to forbid this was accidentally done only for manually specified targets (#6031, @rgrinberg)
• odoc rules now about ODOC_SYNTAX and will rerun accordingly (#6010, fixes #1117, @emillon)

Coq support

These changes, associated with (lang dune 3.5), are specific to coq.

Added

• Add %{coq:...} macro for accessing data about the configuration about Coq. For instance %{coq:version} (#6049, @Alizter)
• Starting with Coq build language 0.6, theories can be built without importing Coq's standard library by including (stdlib no). (#6165 #6164, fixes #6163, @ejgallego @Alizter @LasseBlaauwbroek)

Changed

• Dune no longer considers .aux files as targets during Coq compilation. This means that .aux files are no longer cached. (#6024, fixes #6004, @alizter)
• The test suite for Coq now requires Coq >= 8.16 due to changes in the plugin loading mechanism upstream (which now uses Findlib).
• The (coq.theory ...) stanza will now ensure that for each declared (plugin ...), the META file for it is built before calling coqdep. This enables the use of the new Findlib-based loading method in Coq 8.16; however as of Coq 8.16.0, Coq itself has some bugs preventing this to work yet. (#6167 , workarounds #5767, @ejgallego)

• Fix build on cygwin/i686-w64-mingw32 (#6008, @kit-ty-kate)

• Make dune describe correctly handle overlapping implementations for virtual libraries (#5971, fixes #5747, @esope)

• Building the @check alias should make sure the libraries and executables don't have dependency cycles (#5892, @rgrinberg)

• [ctypes] Add support for the errno parameter using the errno_policy field in the ctypes settings. (#5827, @droyo)

• Fix dune coq top when it is invoked on files from a subdirectory of the directory containing the associated stanza (#5784, fixes #5552, @ejgallego, @rlepigre, @Alizter)

• Fix hint when an invalid module name is found. (#5922, fixes #5273, @emillon)

• The (cat) action now supports several files. (#5928, fixes #5795, @emillon)

• Dune no longer uses shimmed META files for OCaml 5.x, solely using the ones installed by the compiler. (#5916, @dra27)

• Fix handling of the (deps) field in (test) stanzas when there is an .expected file. (#5952, #5951, fixes #5950, @emillon)

• Ignore insignificant filesystem events. This stops RPC in watch mode from flashing errors on insignificant file system events such as changes in the .git/ directory. (#5953, @rgrinberg)

• Fix parsing more error messages emitted by the OCaml compiler. In particular, messages where the excerpt line number started with a blank character were skipped. (#5981, @rgrinberg)

• env stanza: warn if some rules are ignored because they appear after a wildcard rule. (#5898, fixes #5886, @emillon)

• On Windows, XDG_CACHE_HOME is taken to be the FOLDERID_InternetCache if unset, and XDG_CONFIG_HOME and XDG_DATA_HOME are both taken to be FOLDERID_LocalAppData if unset. (#5943, fixes #5808, @nojb)

• Improve parsing of ocamlc errors. We now correctly strip excerpts and parse alerts (#5879, @rgrinberg)

• The (libraries) field of the coq.theory stanza has been renamed to (plugins) and the Coq language version has been bumped to 0.5.

• Sandbox preprocessing, lint, and dialect rules by default. All these rules now require precise dependency specifications (#5807, @rgrinberg)

• Allow list expansion in the pps specification for preprocessing (#5820, @Firobe)

• Add warnings 67-69 to dune's default set of warnings. These are warnings of the form "unused X.." (#5844, @rgrinberg)

• Introduce project "composition" for coq theories. Coq theories in separate projects can now refer to each other when in the same workspace (#5784, @Alizter, @rgrinberg)

• Fix hint message for data_only_dirs that wrongly mentions the unknown constructor data_only (#5803, @lambdaxdotx)

• Fix creating sandbox directory trees by getting rid of buggy memoization (#5794, @rgrinberg, @snowleopard)

• Handle directory dependencies in sandboxed rules. Previously, the parents of these directory dependencies weren't created. (#5754, @rgrinberg)

• Set the exit code to 130 when dune is terminated with a signal (#5769, fixes #5757)

• Support new locations of unix, str, dynlink in OCaml >= 5.0 (#5582, @dra27)

• The coq.theory stanza now produces rules for running coqdoc. Given a theory named mytheory, the directory targets mytheory.html/ and mytheory.tex/ or additionally the aliases @doc and @doc-latex will build the HTML and LaTeX documentation repsectively. (#5695, fixes #3760, @Alizter)

• Coq theories marked as (boot) cannot depend on other theories (#5867, @ejgallego)

• Ignore bigarray in (libraries) with OCaml >= 5.0. (#5526, fixes #5494, @moyodiallo)

• Start with :standard when building the ctypes generated foreign stubs so that we include important compiler flags, such as -fPIC (#5816, fixes #5809).

• Fixed dune describe workspace --with-deps so that it correctly handles Reason files, as well as files any other dialect. (#5701, @esope)

• Disable alerts when compiling code in vendored directories (#5683, @NathanReb)

• Fixed dune describe --with-deps, that crashed when some preprocessing was required in a dune file using per_module. (#5682, fixes #5680, @esope)

• Add $ dune describe pp to print the preprocssed ast of sources. (#5615, fixes #4470, @cannorin)

• Report dune file evaluation errors concurrently. In the same way we report build errors. (#5655, @rgrinberg)

• Watch mode now default to clearing the terminal on rebuild (#5636, fixes, #5216, @rgrinberg)

• The output of jobs that finished but were cancelled is now omitted. (#5631, fixes #5482, @rgrinberg)

• Allows to configure all the default destination directories with ./configure (adds bin, sbin, data, libexec). Use OPAM_SWITCH_PREFIX instead of calling the opam binaries in dune install. Fix handling of multiple libdir in ./configure for handling /usr/lib/ocaml/ and /usr/local/lib/ocaml. In dune install forbid relative directories in libdir, docdir and others specific directory setting because their handling was inconsistent (#5516, fixes #3978 and #5455, @bobot)

• --terminal-persistence=clear-on-rebuild will no longer destroy scrollback on some terminals (#5646, @rgrinberg)

• Add a fmt command as a shortcut of dune build @fmt --auto-promote (#5574, @tmattio)

• Watch mode now tracks copied external files, external directories for dependencies, dune files in OCaml syntax, files used by include stanzas, dune-project, opam files, libraries builtin with compiler, and foreign sources (#5627, #5645, #5652, #5656, #5672, #5691, #5722, fixes #5331, @rgrinberg)

• Improve metrics for cram tests. Include test names in the event and add a category for cram tests (#5626, @rgrinberg)

• Allow specifying multiple licenses in project file (#5579, fixes #5574, @liyishuai)

• Match glob_files only against files in external directories (#5614, fixes #5540, @rgrinberg)

• Add pid's to chrome trace output (#5617, @rgrinberg)

• Fix race when creating local cache directory (#5613, fixes #5461, @rgrinberg)

• Add not to boolean expressions (#5610, fix #5503, @rgrinberg)

• Fix relative dependencies outside the workspace (#4035, fixes #5572, @bobot)

• Allow to specify --prefix via the environment variable DUNE_INSTALL_PREFIX (#5589, @vapourismo)

• Dune-site.plugin: add support for archive(native|byte, plugin) used in the wild before findlib documented plugin(native|byte) in 2015 (#5518, @bobot)

• Fix a bug where Dune would not correctly interpret META files in alternative layout (ie when the META file is named META.$pkg). The Llvm bindings were affected by this issue. (#5619, fixes #5616, @nojb)

• Support (binaries) in (env) in dune-workspace files (#5560, fix #5555, @emillon)

• (mdx) stanza: add support for (locks). (#5628, fixes #5489, @emillon)

• (mdx) stanza: support including files in different directories using relative paths, and provide better error messages when paths are invalid (#5703, #5704, fixes #5596, @emillon)

• Fix ctypes rules for external lib names which aren't valid ocaml names (#5667, fixes #5511, @Khady)

• Fix build on Cygwin. (#5593, fixes 5577, @nojb)

• Fix execution of (system ..) actions on Windows. (#5593, fixes #5523, @nojb)

• Add sourcehut as an option for defining project sources in dune-project files. For example, (source (sourcehut user/repo)). (#5564, @rgrinberg)

• Add dune coq top command for running a Coq toplevel (#5457, @rlepigre)

• Fix dune exec dumping database in wrong directory (#5544, @bobot)

• Always output absolute paths for locations in RPC reported diagnostics (#5539, @rgrinberg)

• Add (deps <deps>) in ctype field (#5346, @bobot)

• Add (include <file>) constructor to dependency specifications. This can be used to introduce dynamic dependencies (#5442, @anmonteiro)

• Ensure that dune describe computes a transitively closed set of libraries (#5395, @esope)

• Add direct dependencies to $ dune describe output (#5412, @esope)

• Show auto-detected concurrency on Windows too (#5502, @MisterDA)

• Fix operations that remove folders with absolute path. This happens when using esy (#5507, @EduardoRFS)

• Dune will not fail if some directories are non-empty when uninstalling. (#5543, fixes #5542, @nojb)

• coqdep now depends only on the filesystem layout of the .v files, and not on their contents (#5547, helps with #5100, @ejgallego)

• The mdx stanza 0.2 can now be used with (implicit_transitive_deps false) (#5558, fixes #5499, @emillon)

• Fix missing parenthesis in printing of corresponding terminal command for (with-outputs-to ) (#5551, fixes #5546, @Alizter)

• Do not enable warnings 63-70 by default (#5476, fixes #5464, @rgrinberg)

• Allow %{read-lines} to introduce dynamic dependencies like %{read}. (#5440, @anmonteiro)

• Look up gmake before make (#5474, fixes #5470, @rgrinberg)

• Handle empty output from getconf (#5473 fixes #5471, @mndrix)

• Depend on any provided foreign_archives for ctypes stub generation (#5475, @mbacarella)

• Fix compilation on MacOS SDK < 10.13. The native watch mode is disabled in such instances (#5431 fix #5430, @rgrinberg)

• Do no add workspace_root to BUILD_PATH_PREFIX_MAP for projects before 3.0 (5448, @rgrinberg)

• Fix performance regression in incremental builds (#5439, @snowleopard)

• Fix digest computation bug introduced in 3.0.1 (#5451, @rgrinberg)

• Remove uchar and seq dummy ocamlfind libraries from dune's builtin library database (#5260, @kit-ty-kate)

• Add a DUNE_DIFF_COMMAND environment variable to match --diff-command command-line parameter (@raphael-proust, fix #5369, #5375)

• Add support for odoc-link rules (#5045, @jonludlam, @lubegasimon)

• Dune will no longer generate documentation for hidden modules (#5045, @jonludlam, @lubegasimon)

• Parse the native_pack_linker field of ocamlc -config (#5281, @TheLortex)

• Fix plugins with dot in the name (#5182, @bobot, review @rgrinberg)

• Don't generate the dune-site build part when not needed (#4861, @bobot, review @kit-ty-kate)

• Fix installation of implementations of virtual libraries (#5150, fix #3636, @rgrinberg)

• Run tests in all modes defined. Previously, jsoo was excluded. (@hhugo, #5049, fix #4951)

• Allow to configure the alias to run the jsoo tests (@hhugo, #5049, #4999)

• Set jsoo compilation flags in the env stanza (@hhugo, #5049, #1613)

• Allow to configure jsoo separate compilation in the env stanza. Previously, it was hard coded to always be enabled in the dev profile. (@hhugo, #5049, fix #970)

• Fix build-info version in jsoo executables (@hhugo, #5049, fix #4444)

• Pass -no-check-prims when building bytecode for jsoo (@hhugo, #5049, #4027)

• Fix jsoo builds when dynamically linked foreign archives are disabled (@hhugo, #5049)

• Disallow empty packages starting from 3.0. Empty packages may be re-enabled by adding the (allow_empty) to the package stanza in the dune-project file. (#4867, fix #2882, @kit-ty-kate, @rgrinberg)

• Add link_flags field to the executable field of inline_tests (#5088, fix #1530, @jvillard)

• In watch mode, use fsevents instead of fswatch on OSX (#4937, #4990, fixes #4896 @rgrinberg)

• Remove inotifywait watch mode backend on Linux. We now use the inotify API exclusively (#4941, @rgrinberg)

• Report cycles between virtual libraries and their implementation (#5050, fixes #2896, @rgrinberg)

• Warn when lang versions have an ignored suffix. (lang dune 2.3.4) or (lang dune 2.3suffix) were silently parsed as 2.3 and we know suggest to remove the prefix. (#5040, @emillon)

• Allow users to specify dynamic dependencies in rules. For example (deps %{read:foo.gen}) (#4662, fixes #4089, @jeremiedimino)

• Sandbox infer rules for menhir. Fixes possible "inconsistent assumptions" errors (#5015, @rgrinberg)

• Experimental support for ctypes stubs (#3905, fixes #135, @mbacarella)

• Fix interpretation of binaries defined in the env stanza. Binaries defined in x/dune wouldn't be visible in `x/*/**/dune. (#4975, fixes #4976, @Leonidas-from-XIV, @rgrinberg)

• Do not list private libraries in package listings (#4945, fixes #4799, @rgrinberg)

• Allow spaces in cram test paths (#4980, fixes #4162, @rgrinberg)

• Improve error handling of misbehaving cram scripts. (#4981, fix #4230, @rgrinberg)

• Fix foreign_stubs inside a tests stanza. Previously, dune would crash when this field was present (#4942, fix #4946, @rgrinberg)

• Add the enabled_if field to inline_tests within the library stanza. This allows us to disable executing the inline tests while still allowing for compilation (#4939, @rgrinberg)

• Generate a dune-project when initializing projects with dune init proj ... (#4881, closes #4367, @shonfeder)

• Allow spaces in the directory argument of the subdir stanza (#4943, fixes #4907, @rgrinberg)

• Add a %{toolchain} expansion variable (#4899, fixes #3949, @rgrinberg)

• Include dependencies of executables when creating toplevels (either dune top or dune utop) (#4882, fixes #4872, @Gopiancode)

• Fixes opam META file requires entry for private libs (#4841, fixes #4839, @toots)

• Fixes dune exec not adding .exe on Windows (#4371, fixes #3322, @MisterDA)

• Allow multiple cinaps stanzas in the same directory (#4460, @rgrinberg)

• Fix $ dune subst in empty git repositories (#4441, fixes #3619, @rgrinberg)

• Improve interpretation of ansi escape sequence when spawning processes (#4408, fixes #2665, @rgrinberg)

• Allow (package pkg) in dependencies even if pkg is an installed package (#4170, @bobot)

• Allow %{version:pkg} to work for external packages (#4104, @kit-ty-kate)

• Add (glob_files_rec <dir>/<glob>) for globbing files recursively (#4176, @jeremiedimino)

• Automatically generate empty .mli files for executables and tests (#3768, fixes #3745, @CraigFe)

• Add ocaml command subgroup for OCaml related commands such as utop, top, and merlin (#3936, @rgrinberg).

• Detect unknown variables more eagerly (#4184, @jeremiedimino)

• Improve location of variables and macros in error messages (#4205, @jeremiedimino)

• Auto-detect dune-project files as dune files in Emacs (#4222, @shonfeder)

• Dune no longer automatically create or edit dune-project files (#4239, fixes #4108, @jeremiedimino)

• Warn if dune-project is not found (fatal in release mode) (#5343, @emillon)

• Cleanup temporary files after running $ dune exec. (#4260, fixes #4243, @rgrinberg)

• Add a new subcommand dune ocaml dump-dot-merlin that prints a mix of all the merlin configuration of a directory (defaulting to the current directory) in the Merlin configuration syntax. (#4250, @voodoos)

• Enable cram tests by default (#4262, @rgrinberg)

• Drop support for opam 1.x (#4280, @jeremiedimino)

• Stop calling ocamlfind to determine the library search path or library installation directory. This makes the behavior of Dune simpler and more reproducible (#4281, @jeremiedimino)

• Remove the external-lib-deps command. This command was only approximative and the cost of maintainance was getting too high. We removed it to make room for new more important features (#4298, @jeremiedimino)

• It is now possible to define action dependencies through a chain of aliases. (#4303, @aalekseyev)

• If an .ml file is not used by an executable, Dune no longer report parsing error in this file (#4330, @jeremiedimino)

• Add support for sandboxing using hard links (#4360, Andrey Mokhov)

• Fix dune crash when subdir is an absolute path (#4366, @anmonteiro)

• Changed the implementation of actions attached to aliases, as in (rule (alias runtest) (action (run ./test))). A visible result for users is that such actions are now memoized for longer. For instance:

  $ echo '(rule (alias runtest) (action (echo "X=%{env:X=0}\n")))` > dune
  $ X=1 dune runtest
  X=1
  $ X=2 dune runtest
  X=2
  $ X=1 dune runtest
  

  Previously, Dune would have re-executed the action again at the last line. Now it remembers the result of the first execution.

• Fix a bug where dune would always re-run all actions that produce symlinks, even if their dependencies did not change. (#4405, @aalekseyev)

• Fix a bug that was causing Dune to re-hash generated files more often than necessary (#4419, @jeremiedimino)

• Fields allowed in the config file are now also allowed in the workspace file (#4426, @jeremiedimino)

• Add options to control how Dune should handle stdout and stderr of actions when then succeed. It is now possible to ask Dune to ignore the stdout of actions when they succeed or to request that the stderr of actions must be empty. This allows to reduce the noise of large builds (#4422, #4515, @jeremiedimino)

• The @all alias no longer depends directly on copies of files from the source directory (#4461, @nojb)

• Allow dune-file as an alternative file name for dune files (needs to be enabled in the dune-project file) (#4428, @nojb)

• Drop support for upgrading jbuilder projects (#4473, @jeremiedimino)

• Extend the environment variable BUILD_PATH_PREFIX_MAP to rewrite the root of the build dir (or sandbox) to /workspace_root (#4466, @jeremiedimino)

• Simplify the implementation of build cache. We stop using the cache daemon to access the cache and instead write to and read from it directly. The new cache implementation is based on Jenga's cache library, which was thoroughly tested on large-scale builds. Using Jenga's cache library will also make it easier for us to port Jenga's cloud cache to Dune. (#4443, #4465, Andrey Mokhov)

• More informative error message when Dune can't read a target that's supposed to be produced by the action. Old message is still produced on ENOENT, but other errors deserve a more detailed report. (#4501, @aalekseyev)

• Fixed a bug where a sandboxed action would fail if it declares no dependencies in its initial working directory or any directory it chdirs into. (#4509, @aalekseyev)

• Fix a crash when clearing temporary directories (#4489, #4529, Andrey Mokhov)

• Dune now memoizes all errors when running in the file-watching mode. This speeds up incremental rebuilds but may be inconvenient in rare cases, e.g. if a build action fails due to a spurious error, such as running out of memory. Right now, the only way to force such actions to be rebuilt is to restart Dune, which clears all memoized errors. In future, we would like to provide a way to rerun all actions failed due to errors without restarting the build, e.g. via a Dune RPC call. (#4522, Andrey Mokhov)

• Remove dune compute. It was broken and unused (#4540, @jeremiedimino)

• No longer generate an approximate merlin files when computing the ocaml flags fails, for instance because they include the contents of a file that failed to build. This was a niche feature and it was getting in the way of making Dune's core better. (#4607, @jeremiedimino)

• Make Dune display the progress indicator in all output modes except quiet (#4618, @aalekseyev)

• Report accurate process timing information in trace mode (enabled with --trace-file) (#4517, @rgrinberg)

• Do not log live_words and free_words in trace file. This allows using Gc.quick_stat which does not scan the heap. (#4643, @emillon)

• Don't let command run by Dune observe the environment variable INSIDE_EMACS in order to improve reproducibility (#4680, @jeremiedimino)

• Fix root_module when used in public libraries (#4685, fixes #4684, @rgrinberg, @CraigFe)

• Fix root_module when used with preprocessing (#4683, fixes #4682, @rgrinberg, @CraigFe)

• Display Coq profile flags in dune printenv (#4767, @ejgallego)

• Introduce mdx stanza 0.2, requiring mdx >= 1.9.0, with a new generic deps field and the possibility to statically link libraries in the test executable. (#3956, #5391, fixes #3955)

• Improve lookup of optional or disabled binaries. Previously, we'd treat every executable with missing libraries as optional. Now, we treat make sure to look at the library's optional or enabled_if status (#4786).

• Always use 7 char hash prefix in build info version (#4857, @jberdine, fixes #4855)

• Allow to explicitly disable/enable the use of dune subst by adding a new (subst <disable|enable>) stanza to the dune-project file. (#4864, @kit-ty-kate)

• Simplify the way dune discovers the root of the workspace. It now stops at the first dune-workspace file it encounters, and fails if it finds neither a dune-workspace nor a dune-project file (#4921, fixes #4459, @jeremiedimino)

• Dune no longer reads installed META files for libraries distributed with the compiler, instead using its own internal database. (#4946, @nojb)

• Add support for (empty_module_interface_if_absent) in executable and library stanzas. (#4955, @nojb)

• Add support for %{bin-available:...} (#4995, @jeremiedimino)

• Make sure running git or hg in a sandboxed action, such as a cram test cannot escape the sandbox and pick up some random git or mercurial repository on the file system (#4996, @jeremiedimino)

• Allow %{read:...} in more places such as (enabled_if ...) (#4994, @jeremiedimino)

• Run each action in its own process group so that we don't leave stray processes behind when killing actions (#4998, @jeremiedimino)

• Add an option expand_aliases_in_sandbox (#5003, @jeremiedimino)

• Allow to cancel the initial scan via Control+C (#4460, fixes #4364 @jeremiedimino)

• Add experimental support for directory targets (#3316, #5025, Andrey Mokhov), enabled via (using directory-targets 0.1) in dune-project.

• Delete old promote-into, promote-until-clean and promote-until-clean-into syntax (#5091, Andrey Mokhov).

• Add link_flags in the env stanza (#5215)

• Bootstrap: ignore errors when trying to remove generated files. (#5407, @damiendoligez)