[new release] dune (15 packages) (3.20.0~alpha4)

[maiste]

Fast, portable, and opinionated build system

• Project page: https://github.com/ocaml/dune
• Documentation: https://dune.readthedocs.io/

CHANGES:

Fixed

• Stop re-running cram tests after promotion when it's not necessary (fix(cram): do not re-run tests unnecessarily dune#11994,
  @rgrinberg)

• fix: $ dune subst should not fail when adding the version field in opam
  files (Fix #11045 dune#11801, fixes Regression in #11028 when using dune subst on a project with an opam file dune#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 (Terminate process group after cram execution dune#11841, fixes Background tasks in Cram tests are not terminated dune#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. (feature: tests stanzas produce aliases dune#11558, grants part of Automatically add aliases for expect tests dune#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. (feature: add aliases for inline tests dune#11109, partially fixes Automatically add aliases for expect tests dune#10239, @Alizter)

• feature: $ dune subst use version from dune-project when no version
  control repository has been detected (Fix #11045 dune#11801, @btjorge)

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

• Introduce %{os}, %{os_version}, %{os_distribution}, and %{os_family}
  percent forms. These have the same values as their opam counterparts.
  (feature: share os family of vars with rules dune#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. (Add (implicit_transitive_deps false-if-hidden-includes-supported) dune#11866, fixes Enable (implicit_transitive_deps false) only if OCaml version supports -H? dune#11212, @nojb)

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

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

• Added 'empty' alias which contains no targets. (feature: empty alias dune#11556 fix: empty alias check for 3.20 dune#11952 test: empty alias in alias stanza dune#11955 doc: document empty alias dune#11956,
  grants an empty target for easier scripting dune#4161, @Alizter and @rgrinberg)

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

• Add --alias and --alias-rec flags as an alternative to the @@ and @
  syntax in the command line (feature: add --alias as an argument for building aliases dune#12043, fixes Current Dune alias syntax can't work reliably on Windows dune#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.
  (feat(cram): timeout for cram tests dune#12041, @Alizter)

Changed

• Format long lists in s-expressions to fill the line instead of
  formatting them in a vertical way (Tweak dune file formatting: avoid pure vertical layout when formatting wrapped lists dune#10892, fixes auto formatting of run shouldn't split its content into one word per line dune#10860, @nojb)

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

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

• Stop emitting empty module group wrapper .js file in melange.emit
  (melange: don't emit module group wrapper as a JS file in melange.emit dune#11987, fixes test(melange): show melange emits the (empty) module group wrapper dune#11986, @anmonteiro)

[maiste]

@Alizter I have done the comparison with the previous release, and it seems the regression is fixed. If that's good for you too, I'll close the PR and open the definitive 3.20 one.

[Alizter]

@mseri Could you double check if we have any new failures? I am not quite sure how to interpret all the failing jobs to see if they are relevant for us.

[shonfeder]

Is it possible that this failure from odoc3 is relevant? https://opam.ci.ocaml.org/github/ocaml/opam-repository/commit/e2e946ed909ce4d2c3e1e35bbaff78b566760128/variant/compilers,5.3,dune.3.20.0~alpha4,revdeps,odoc.3.0.0

See, e.g.,

### output ###
# (cd _build/default/src/html_support_files && /home/opam/.opam/5.3/bin/ocaml-crunch . -e js -e css -e ttf -e woff2 -o odoc_html_support_files.ml -m plain)
# Generating odoc_html_support_files.ml
# Skipping generation of .mli
# File "test/generators/link.dune.inc", line 1, characters 0-0:
# /usr/bin/git --no-pager diff --no-index --color=always -u _build/default/test/generators/link.dune.inc _build/default/test/generators/link.dune.inc.gen
# diff --git a/_build/default/test/generators/link.dune.inc b/_build/default/test/generators/link.dune.inc.gen
# index 15a2968..bd7b1d4 100644
# --- a/_build/default/test/generators/link.dune.inc
# +++ b/_build/default/test/generators/link.dune.inc.gen
# @@ -812,15 +812,7 @@
#    (targets Alerts.html.gen Alerts-Top1.html.gen)
#    (package odoc)
#    (action
# -   (run
# -    odoc
# -    html-generate
# -    --indent
# -    --flat
# -    --extra-suffix
# -    gen
# -    -o
# -    .
# +   (run odoc html-generate --indent --flat --extra-suffix gen -o .
#      %{dep:../alerts.odocl}))
#    (enabled_if
#     (>= %{ocaml_version} 4.04)))

Am I correct in thinking we just need an upper bound on odoc 3 for this?

[shonfeder]

Nothing else looks relevant to me, after comparing the diff of revdep failures against those for 3.19 in https://github.com/ocaml/dune/wiki/Reverse-dependencies-CI-logs .

[maiste]

Am I correct in thinking we just need an upper bound on odoc 3 for this?

Maybe, this is only a formatting issue in the tests due to ocaml/odoc#1338. The dune file formatting changes in 3.20.0 meaning it is breaking the test as it formats differently. It might require a bump in the dune version on the odoc side in prevision for the next odoc release. There are some explorations on the Dune side to remove this issue.

[maiste]

Closing in favor of the official release.