Bug#1152880: librsvg FTCBFS: multiple reasons

[Simon McVittie]

On Mon, 02 Nov 2026 at 16:38:31 +0100, Helmut Grohne wrote:
>At this point, Build-Depends can be installed. Unfortunately, meson
>refuses to configure. It objects to enabling the introspection and vala
>features as we cannot run host binaries.

Actually we can, if `meson env2mfile` is used to generate a cross-file 
that sets exe_wrapper to the Debian-specific 
MULTIARCH-cross-exe-wrapper. This is a long-standing feature request for 
debhelper, which currently uses the deprecated debcrossgen tool, which 
the meson maintainer doesn't want to improve any further (see also 
#1111001, https://salsa.debian.org/debian/debhelper/-/merge_requests/127) 
but `export MESON_USE_NEW_CROSSGEN=1` in debian/rules should be enough 
to make this work.

I think using `meson env2mfile` would be preferable to patching the 
upstream build system to pretend that introspection can work without the 
ability to run host binaries.

>Then, the build proceeds quite far until meson launches the wrong
>vapigen. This is not a bug in librsvg but in meson itself and it is
>reported as #1126007.

If the build uses `meson env2mfile`, then recent Meson should resolve 
this without necessarily needing to look up vapigen via pkg-config, 
because https://github.com/mesonbuild/meson/pull/15056 was merged.

(Or the cross-file
/usr/share/meson/cross/${DEB_HOST_GNU_TYPE}-vala.ini is also available.)

     smcv