There's an upstream bug (https://bugs.astron.com/view.php?id=257) where XZ compression is incorrectly detected as application/octet-stream (the default) rather than application/x-xz. This has been resolved upstream in HEAD (and the commit is at https://github.com/file/file/commit/9b0459afab309a82aa4e46f73a4e50dd641f3d39) but currently breaks compression detection.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=bb949123596216a8af1a18b1ba4f396919a2d976 commit bb949123596216a8af1a18b1ba4f396919a2d976 Author: Lars Wendler <polynomial-c@gentoo.org> AuthorDate: 2021-04-21 09:41:58 +0000 Commit: Lars Wendler <polynomial-c@gentoo.org> CommitDate: 2021-04-21 09:42:48 +0000 sys-apps/file: Revbump to fix xz magic Thanks-to: Mike Auty <ikelos@gentoo.org> Closes: https://bugs.gentoo.org/784773 Signed-off-by: Lars Wendler <polynomial-c@gentoo.org> .../file/{file-5.40.ebuild => file-5.40-r1.ebuild} | 1 + sys-apps/file/files/file-5.40-xz_magic.patch | 37 ++++++++++++++++++++++ 2 files changed, 38 insertions(+)