Control: tags -1 confirmed
On 06/02/2026 15:18, Jeremy Bícha wrote:
Package: release.debian.org
User: [email protected]
Usertags: transition
Control: affects -1 + src:gdk-pixbuf
X-Debbugs-Cc: [email protected]
In the middle of last year, gdk-pixbuf switched its default image
loaders to use glycin. [1] The Debian GNOME team has prepared
packaging in experimental and is ready to upload this change to
Unstable. This isn't a typical transition: there is no soname bump and
nothing needs to be rebuilt. Since gdk-pixbuf is fundamental to
graphics for everything that uses GTK, I thought it best to keep the
Release Team informed and to ask for approval to proceed. Ubuntu 26.04
LTS (devel) is switching gdk-pixbuf to glycin now also.
Generally speaking, glycin supports as many image formats [2] as the
legacy gdk-pixbuf loaders. It actually supports a few more (like
OpenEXR). There are some obscure formats that are not supported, like
qtif (QuickTime) and icns (historically used by macOS but Apple is
recommending Asset catalogs instead). Both of those formats were moved
to gdk-pixbuf's "others" category in 2024 and disabled by default
upstream since they weren't well supported. (Debian had been
continuing to include those loaders until now.) Debian's gdk-pixbuf
continues to support the xbm/xpm format which is still used for older
X apps.
There is one format supported by glycin upstream that Debian's glycin
doesn't yet support: JPEG2000. This format hasn't been supported by
Debian's gdk-pixbuf for a decade, but will be supported soon (waiting
on NEW queue processing). [3]
glycin is already used in Debian 13 for GNOME's new default image viewer, loupe.
We have enabled glycin for all Debian release architectures (excluding
loong64 because it is still being bootstrapped). For simplicity, we
are still using the legacy loaders instead of glycin on all Debian
ports. glycin requires rustc. glycin's packaging also currently
requires up-to-date gtk4 but that can be fixed later.
A few Debian packages will need adjustments in their build tests for
gdk-pixbuf+glycin. Examples:
- mat2 needs a Debian upload to disable 2 tests
https://salsa.debian.org/pkg-privacy-team/mat2/-/merge_requests/7
- webp-pixbuf-loader is an example of a package whose only purpose was
to extend gdk-pixbuf's native loaders. It needed its autopkgtests and
build tests disabled. I expect we'll keep this package in unstable
only since it can be used by ports but otherwise is useless in Debian.
- denemo has a build test and autopkgtest failure [4] but denemo is
not in Testing
All other triggered autopkgtests appear to pass. Some other
autopkgtests may fail because their packages indirectly depend on
gdk-pixbuf through gtk.
Go ahead.
Emilio
