3.21.0~alpha2

CHANGES:

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)

• 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)

• 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)

• 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)

• 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)

• 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)

• 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)