3.20.0 release tracker

[maiste]

Known blockers

• All x.y.z changelogs merged [3.20] prepare 3.20~alpha0 release #12083
• Run mirage tests https://github.com/ocaml/dune/actions/runs/16569472557
• Detected regression:
  • [3.20] backport: PR #12121 #12127
  • github.com/test: include_subdirs unqualified duplicates cram rules #12142

Release

• Triage (ensure it does not break anything):
• Alpha 4: [new release] dune (15 packages) (3.20.0~alpha4) opam-repository#28333
• Alpha 3: [new release] dune (15 packages) (3.20.0~alpha3) opam-repository#28302
• Alpha 2: [new release] dune (15 packages) (3.20.0~alpha2) opam-repository#28298
• Alpha 1: [new release] dune (15 packages) (3.20.0~alpha1) opam-repository#28276
• Alpha 0: [new release] dune (15 packages) (3.20.0~alpha0) opam-repository#28267
• Update dune changelog to 3.20.0 on 3.20 branch [3.20] prepare 3.20.0 release #12216
• Open then pull request on opam-repository [new release] dune (15 packages) (3.20.0) opam-repository#28357
• Update nix-overlays with the new version Update Dune 3.20.0 nix-ocaml/nix-overlays#2127 (bump directly to 3.20.1 instead)

Post-release

• Merge dune changelog in main chore: backport 3.20.0 changelog #12240
• Update ocaml.org changelog changelog: release dune.3.20.0 ocaml.org#3265
• Write a post about the release on Discuss https://discuss.ocaml.org/t/ann-dune-3-20/17150
• Store the revdeps error file in the logs https://github.com/ocaml/dune/wiki/Reverse-dependencies-CI-logs
• Create a next release milestone
• Increase lang dune number chore: bump to 3.21 #12198

Last stage

• Close tracking issue
• Close milestone