mypy 2.x for Debian
-------------------

Mypy 2.x include a rust-based native parser that is not yet packaged in Debian.
Until that library is packaged [1], the Debian package of mypy 2.x does not
have both the native parser and parallel parsing features, and their
command-line options (`--native-parser`, `--num-workers`) are silently accepted
and ignored. The parallel parsing feature requires the native parser, so it had
to also be disabled.

[1] The mypy native parsing Python library "ast_serialize" requires private Rust
crates from "ruff" that are not published independently (on crates.io or
similar) nor distributed (vendored) by ast_serialize itself. The Debian package
for ruff[2] is quite behind the version pinned by ast_serialize and is
currently (2026-05-15) not even in Debian's "testing" distribution.
Additionally, it is likely that whatever is blocking the ruff packagers from
upgrading to more recent releases would be a challenge for packaging the
specific private crates needed by ast_serialize.

https://github.com/mypyc/ast_serialize/issues/49
https://bugs.debian.org/1074734  Latest update on ruff packaging

[2] https://tracker.debian.org/pkg/ruff

-- Michael R. Crusoe <crusoe@debian.org>, Fri, 15 May 2026 12:09:17 +0200
