…ne-action-plugin, dune-private-libs and dune-glob (2.8.0)

CHANGES:

- `dune rules` accepts aliases and other non-path rules (ocaml/dune#4063, @mrmr1993)

- Action `(diff reference test_result)` now accept `reference` to be absent and
  in that case consider that the reference is empty. Then running `dune promote`
  will create the reference file. (ocaml/dune#3795, @bobot)

- Ignore special files (BLK, CHR, FIFO, SOCKET), (ocaml/dune#3570, fixes ocaml/dune#3124, ocaml/dune#3546,
  @ejgallego)

- Experimental: Simplify loading of additional files (data or code) at runtime
  in programs by introducing specific installation sites. In particular it allow
  to define plugins to be installed in these sites. (ocaml/dune#3104, ocaml/dune#3794, fixes ocaml/dune#1185,
  @bobot)

- Move all temporary files created by dune to run actions to a single directory
  and make sure that actions executed by dune also use this directory by setting
  `TMPDIR` (or `TEMP` on Windows). (ocaml/dune#3691, fixes ocaml/dune#3422, @rgrinberg)

- Fix bootstrap script with custom configuration. (ocaml/dune#3757, fixes ocaml/dune#3774, @marsam)

- Add the `executable` field to `inline_tests` to customize the compilation
  flags of the test runner executable (ocaml/dune#3747, fixes ocaml/dune#3679, @lubegasimon)

- Add `(enabled_if ...)` to `(copy_files ...)` (ocaml/dune#3756, @nojb)

- Make sure Dune cleans up the status line before exiting (ocaml/dune#3767,
  fixes ocaml/dune#3737, @alan-j-hu)

- Add `{gitlab,bitbucket}` as options for defining project sources with `source`
  stanza `(source (<host> user/repo))` in the `dune-project` file.  (ocaml/dune#3813,
  @rgrinberg)

- Fix generation of `META` and `dune-package` files when some targets (byte,
  native, dynlink) are disabled. Previously, dune would generate all archives
  for regardless of settings. (ocaml/dune#3829, ocaml/dune#4041, @rgrinberg)

- Do not run ocamldep to for single module executables & libraries. The
  dependency graph for such artifacts is trivial (ocaml/dune#3847, @rgrinberg)

- Fix cram tests inside vendored directories not being interpreted correctly.
  (ocaml/dune#3860, fixes ocaml/dune#3843, @rgrinberg)

- Add `package` field to private libraries. This allows such libraries to be
  installed and to be usable by other public libraries in the same project
  (ocaml/dune#3655, fixes ocaml/dune#1017, @rgrinberg)

- Fix the `%{make}` variable on Windows by only checking for a `gmake` binary
  on UNIX-like systems as a unrelated `gmake` binary might exist on Windows.
  (ocaml/dune#3853, @kit-ty-kate)

- Fix `$ dune install` modifying the build directory. This made the build
  directory unusable when `$ sudo dune install` modified permissions. (fix
  ocaml/dune#3857, @rgrinberg)

- Fix handling of aliases given on the command line (using the `@` and `@@`
  syntax) so as to correctly handle relative paths. (ocaml/dune#3874, fixes ocaml/dune#3850, @nojb)

- Allow link time code generation to be used in preprocessing executable. This
  makes it possible to use the build info module inside the preprocessor.
  (ocaml/dune#3848, fix ocaml/dune#3848, @rgrinberg)

- Correctly call `git ls-tree` so unicode files are not quoted, this fixes
  problems with `dune subst` in the presence of unicode files. Fixes ocaml/dune#3219
  (ocaml/dune#3879, @ejgallego)

- `dune subst` now accepts common command-line arguments such as
  `--debug-backtraces` (ocaml/dune#3878, @ejgallego)

- `dune describe` now also includes information about executables in addition to
  that of libraries. (ocaml/dune#3892, ocaml/dune#3895, @nojb)

- instrumentation backends can now receive arguments via `(instrumentation
  (backend <name> <args>))`. (ocaml/dune#3906, ocaml/dune#3932, @nojb)

- Tweak auto-formatting of `dune` files to improve readability. (ocaml/dune#3928, @nojb)

- Add a switch argument to opam when context is not default. (ocaml/dune#3951, @tmattio)

- Avoid pager when running `$ git diff` (ocaml/dune#3912, @AltGr)

- Add `(root_module ..)` field to libraries & executables. This makes it
  possible to use library dependencies shadowed by local modules (ocaml/dune#3825,
  @rgrinberg)

- Allow `(formatting ...)` field in `(env ...)` stanza to set per-directory
  formatting specification. (ocaml/dune#3942, @nojb)

- [coq] In `coq.theory`, `:standard` for the `flags` field now uses the
  flags set in `env` profile flags (ocaml/dune#3931 , @ejgallego @rgrinberg)

- [coq] Add `-q` flag to `:standard` `coqc` flags , fixes ocaml/dune#3924, (ocaml/dune#3931 , @ejgallego)

- Add support for Coq's native compute compilation mode (@ejgallego, ocaml/dune#3210)

- Add a `SUFFIX` directive in `.merlin` files for each dialect with no
  preprocessing, to let merlin know of additional file extensions (ocaml/dune#3977,
  @vouillon)

- Stop promoting `.merlin` files. Write per-stanza Merlin configurations in
  binary form. Add a new subcommand `dune ocaml-merlin` that Merlin can use to
  query the configuration files. The `allow_approximate_merlin` option is now
  useless and deprecated. Dune now conflicts with `merlin < 3.4.0` and
  `ocaml-lsp-server < 1.3.0` (ocaml/dune#3554, @voodoos)

- Configurator: fix a bug introduced in 2.6.0 where the configurator V1 API
  doesn't work at all when used outside of dune. (ocaml/dune#4046, @aalekseyev)

- Fix `libexec` and `libexec-private` variables. In cross-compilation settings,
  they now point to the file in the host context. (ocaml/dune#4058, fixes ocaml/dune#4057,
  @TheLortex)

- When running `$ dune subst`, use project metadata as a fallback when package
  metadata is missing. We also generate a warning when `(name ..)` is missing in
  `dune-project` files to avoid failures in production builds.

- Remove support for passing `-nodynlink` for executables. It was bypassed in
  most cases and not correct in other cases in particular on arm32.
  (ocaml/dune#4085, fixes ocaml/dune#4069, fixes ocaml/dune#2527, @emillon)

- Generate archive rules compatible with 4.12. Dune longer attempt to generate
  an archive file if it's unnecessary (ocaml/dune#3973, fixes ocaml/dune#3766, @rgrinberg)

- Fix generated Merlin configurations when multiple preprocessors are defined
  for different modules in the same folder. (ocaml/dune#4092, fixes ocaml/dune#2596, ocaml/dune#1212 and
  ocaml/dune#3409, @voodoos)

- Add the option `use_standard_c_and_cxx_flags` to `dune-project` that 1.
  disables the unconditional use of the `ocamlc_cflags` and `ocamlc_cppflags`
  from `ocamlc -config` in C compiler calls, these flags will be present in the
  `:standard` set instead; and 2. enables the detection of the C compiler family
  and populates the `:standard` set of flags with common default values when
  building CXX stubs. (ocaml/dune#3875, ocaml/dune#3802, fix ocaml/dune#3718 and ocaml/dune#3528, @voodoos)