Dune 1.9.2

Put back library variants in development mode. We discovered a serious unexpected issue and we might need to adjust the design of this feature before we are ready to commit to a final version. Users will need to write (using library_variants 0.1) in their dune-project file if they want to use it before the design is finalized. (#2116, @diml)

Forbid to attach a variant to a library that implements a virtual library outside the current project (#2104, @rgrinberg)

Fix a bug where dune install would install man pages to incorrect paths when compared to opam-installer. For example dune now installs (foo.1 as man1/foo.1) correctly and previously that was installed to man1/man1/foo.1. (#2105, @aalekseyev)

Do not fail when a findlib directory doesn't exist (#2101, fix #2099, @diml)

[coq] Rename (coqlib ...) to (coq.theory ...), support for coqlib will be dropped in the 1.0 version of the Coq language (#2055, @ejgallego)

Fix crash when calculating library dependency closure (#2090, fixes #2085, @rgrinberg)

Clean up the special support for findlib.dynload. Before, Dune would simply match on the library name. Now, we only match on the findlib package name when the library doesn't come from Dune. Someone writing a library called findlib.dynload with Dune would have to add (special_builton_support findlib_dynload) to trigger the special behavior. (#2115, @diml)

Include permissions in the digest of targets and dependencies (#2121, fix #1426, @rgrinberg, @xclerc)