librsvg 2.44.15 FTBFS in focal

[Olivier Tilloy]

focal currently has rustc 1.38 (1.38.0+dfsg0.2+llvm-0ubuntu1), and librsvg 2.44.15 fails to build from source with this version. It built fine with rustc 1.37 (although there was a unit test failure on ppc64el, which prevented it from leaving focal-proposed, see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=942022).

The upstream commit that addresses this is https://gitlab.gnome.org/GNOME/librsvg/commit/de26c4d8.
I backported it and added another patch to update the vendored crates in the source tarball accordingly, and the build succeeds again, but unit tests consistently fail, on all architectures.

The upstream commit message says « Although you should rather be using the 2.46 branch of librsvg as 2.44 is EOL », so we should probably update librsvg in debian to 2.46 indeed.

[Olivier Tilloy (osomon)]

Patch for the upstream commit (https://gitlab.gnome.org/GNOME/librsvg/commit/de26c4d8).

[Olivier Tilloy (osomon)]

Follow-up patch that updates the vendored crates in the source tarball accordingly.

[Olivier Tilloy (osomon)]

Build log with the above two patches applied, unit tests fail.

[Olivier Tilloy (osomon)]

The unit test failures are related to https://gitlab.gnome.org/GNOME/librsvg/issues/511 and https://gitlab.gnome.org/GNOME/librsvg/issues/512.

A temporary workaround until upstream implements a clean way to skip the reftests is https://salsa.debian.org/gnome-team/librsvg/merge_requests/3.

[Olivier Tilloy (osomon)]

Ready for review and sponsoring in Debian: https://salsa.debian.org/gnome-team/librsvg/merge_requests/5