Bug#1054888: fontconfig: FTBFS if bubblewrap is installed

[Simon McVittie]

Control: retitle -1 fontconfig: FTBFS if bubblewrap is installed

On Thu, 15 Jan 2026 at 02:54:26 +0100, Vincent Lefevre wrote:
>On 2023-10-27 22:12:13 -0500, David (Plasma) Paul wrote:
>> fontconfig does not list uuid-runtime among its build dependencies, but
>> it does declare a Build-Depends on uuid-dev which Depends on libuuid1
>> which Recommends uuid-runtime, so this issue only arises when
>> Recommended packages aren't automatically installed.
>
>libuuid1 no longer recommends uuid-runtime. Now it just has
>"Suggests: uuid-runtime". So I'm raising the severity to
>serious, because after a usual installation, one gets a FTBFS.

The recent uploads to unstable (most recently to fix unrelated RC bugs by 
re-integrating past NMUs) built successfully on the official buildds, 
including running tests, without adding this Build-Depends. According to 
the build logs (search for "Package versions"), uuid-runtime was not 
installed in the build container.

Looking at upstream's test script, probably the scenario in which it 
fails to build is a non-minimal environment where bubblewrap *is* 
installed, but uuid-runtime is not?

The test script likely also needs patching to skip bubblewrap-related 
parts if bubblewrap (bwrap) is installed but doesn't work - due to 
kernel restrictions, normally bubblewrap can't work when running in a 
chroot, or in most container environments. When I tried to build with 
`sbuild --add-depends=bubblewrap`, the test failed sooner than it would 
have done from a missing uuidgen, with these messages:

Running: Basic functionality with the bind-mounted cache dir
bwrap: No permissions to create new namespace, likely because the kernel does not allow non-privileged user namespaces. See <https://deb.li/bubblewrap> or <file:///usr/share/doc/bubblewrap/README.Debian.gz>.
Aborting from 'Basic functionality with the bind-mounted cache dir' with the exit code 1
FAIL run-test.sh (exit status: 1)

A good way to probe whether bubblewrap can work is:

     bwrap --dev-bind / / true

which will exit 0 if it works, or nonzero if it can't.

     smcv