Package: libflac-dev
Version: 1.5.0+ds-4
Severity: serious
Tags: ftbfs
Control: affects -1 + src:libsdl3-mixer
Reproducible by attempting to build (for example)
libsdl3-mixer/experimental. This package Build-Depends on libflac-dev
and uses the C libFLAC, but does not use libFLAC++.
Expected result: it successfully detects libFLAC, as it did in the past.
Actual result (edited to remove blank lines):
>-- Found Vorbis: /usr/lib/x86_64-linux-gnu/libvorbisfile.so
>-- Using system vorbisfile
>CMake Error at /usr/lib/x86_64-linux-gnu/cmake/FLAC/targets.cmake:110
>(message):
> The imported target "FLAC::FLAC++" references the file
> "/usr/lib/x86_64-linux-gnu/libFLAC++.so.11.0.0"
> but this file does not exist. Possible reasons include:
> * The file was deleted, renamed, or moved to another location.
> * An install or uninstall procedure did not complete successfully.
> * The installation package was faulty and contained
> "/usr/lib/x86_64-linux-gnu/cmake/FLAC/targets.cmake"
> but not all the files it references.
>Call Stack (most recent call first):
> /usr/lib/x86_64-linux-gnu/cmake/FLAC/flac-config.cmake:42 (include)
> CMakeLists.txt:565 (find_package)
>-- Configuring incomplete, errors occurred!
I suspect that other packages like libsndfile will also be affected by
this issue, but I haven't tested others.
I see these options for how to resolve this:
1. libflac-dev contains development files for both FLAC and FLAC++.
libflac++-dev becomes an empty transitional package depending on
libflac-dev.
2. Keep libflac-dev and libflac++-dev separate.
Ask upstream to convert the FLAC::FLAC++ target into FLAC++::FLAC++
in its own CMake module, and install that into libflac++-dev. This
would be a breaking change for CMake users of FLAC++, which would now
have to use find_package(FLAC++). (But there are not many users of
libflac++, compared with users of libflac.)
3. Move the CMake files to libflac++-dev. This would partially revert
the fix for #1118470: dependent packages would be able to
find_package(FLAC) without supplying their own FindFLAC.cmake, but
only if they B-D on libflac++-dev, even if the only library they
actually wanted is the C libflac.
4. Somehow make the FLAC::FLAC++ target only be defined if the
appropriate library is actually installed (I don't know how feasible
this is, I don't know CMake very well).
5. (maybe others, I don't know CMake very well)
A superficial autopkgtest similar to libsdl3's debian/tests/cmake could
have detected this, and might be a good idea to have available to avoid
future regressions when changing the build system around.
Thanks,
smcv
