cmake in sniper fails to locate libogg and libvorbis

[Gelmo]

Your system information

• Steam Runtime Version: Sniper
• Distribution: Using the image registry.gitlab.steamos.cloud/steamrt/sniper/sdk:latest

Please describe your issue in as much detail as possible:

We are building our game in the Sniper container per the documentation at GitLab. We have Cmake find several packages, for example:

find_package(ZLIB REQUIRED GLOBAL)

However, this does not work for ogg or vorbis:

find_package(Ogg REQUIRED GLOBAL)

 CMake Error at extern/CMakeLists.txt:38 (find_package):
   By not providing "FindOgg.cmake" in CMAKE_MODULE_PATH this project has
   asked CMake to find a package configuration file provided by "Ogg", but
   CMake did not find one.

   Could not find a package configuration file provided by "Ogg" with any of
   the following names:

     OggConfig.cmake
     ogg-config.cmake

   Add the installation prefix of "Ogg" to CMAKE_PREFIX_PATH or set "Ogg_DIR"
   to a directory containing one of the above files.  If "Ogg" provides a
   separate development package or SDK, be sure it has been installed.

find_package(Vorbis REQUIRED GLOBAL)

   Could not find a package configuration file provided by "Vorbis" with any
   of the following names:

     VorbisConfig.cmake
     vorbis-config.cmake

   Add the installation prefix of "Vorbis" to CMAKE_PREFIX_PATH or set
   "Vorbis_DIR" to a directory containing one of the above files.  If "Vorbis"
   provides a separate development package or SDK, be sure it has been
   installed.

When browsing the Sniper image, we see that vorbis is missing as well.

find /usr -iname "*sdl*cmake*" -o -iname "*zlib*cmake*" -o -iname "*freetype*cmake*" -o -iname "*vorbis*cmake*" -o -iname "*openal*cmake*" -o -iname "*curl*cmake*" -o -iname "*stb*cmake*"

/usr/lib/i386-linux-gnu/cmake/SDL2/sdl2-config-version.cmake
/usr/lib/i386-linux-gnu/cmake/SDL2/sdl2-config.cmake
/usr/lib/i386-linux-gnu/cmake/SDL2_image/sdl2_image-config-version.cmake
/usr/lib/i386-linux-gnu/cmake/SDL2_image/sdl2_image-config.cmake
/usr/lib/i386-linux-gnu/cmake/SDL2_mixer/sdl2_mixer-config-version.cmake
/usr/lib/i386-linux-gnu/cmake/SDL2_mixer/sdl2_mixer-config.cmake
/usr/lib/i386-linux-gnu/cmake/SDL2_ttf/sdl2_ttf-config-version.cmake
/usr/lib/i386-linux-gnu/cmake/SDL2_ttf/sdl2_ttf-config.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2/sdl2-config-version.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2/sdl2-config.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2_image/sdl2_image-config-version.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2_image/sdl2_image-config.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2_mixer/sdl2_mixer-config-version.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2_mixer/sdl2_mixer-config.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2_ttf/sdl2_ttf-config-version.cmake
/usr/lib/x86_64-linux-gnu/cmake/SDL2_ttf/sdl2_ttf-config.cmake
/usr/share/cmake-3.25/Modules/FindCURL.cmake
/usr/share/cmake-3.25/Modules/FindFreetype.cmake
/usr/share/cmake-3.25/Modules/FindSDL_gfx.cmake
/usr/share/cmake-3.25/Modules/FindSDL_image.cmake
/usr/share/cmake-3.25/Modules/FindSDL_net.cmake
/usr/share/cmake-3.25/Modules/FindOpenAL.cmake
/usr/share/cmake-3.25/Modules/FindSDL.cmake
/usr/share/cmake-3.25/Modules/FindSDL_mixer.cmake
/usr/share/cmake-3.25/Modules/FindSDL_sound.cmake
/usr/share/cmake-3.25/Modules/FindSDL_ttf.cmake
/usr/share/cmake-3.25/Modules/FindZLIB.cmake
/usr/share/cmake-3.25/Modules/TestBigEndian.cmake

[Gelmo]

Maybe this is related - xiph/vorbis#69 - And if so, I suppose that means it won't be fixed until SLR is newer than Debian 11. I guess we'll need to add our own FindOgg.cmake and FindVorbis.cmake

[Gelmo]

Likely related - xiph/ogg#82

[smcv]

The versions of libogg and libvorbis in sniper are correctly installed, but because they were built with Autotools, they didn't generate CMake-specific metadata describing how to find them.

For the Steam Runtime environment, please locate these libraries using pkg-config, which has cross-build-system metadata discovery that can be used from Autotools, CMake, Meson and probably others. The versions of libogg and libvorbis in sniper do provide pkg-config metadata.

https://cmake.org/cmake/help/latest/module/FindPkgConfig.html suggests that pkg_check_modules (OGG ogg) should set variables like OGG_FOUND, OGG_CFLAGS and OGG_LIBRARIES, and similar for vorbis.

A few libraries (like SDL and dbus) generate CMake-specific metadata even when they were built with some other build system, but this is not universal and cannot be relied on: it requires the maintainer of every library to write CMake-specific build system code, even if they do not use or recommend CMake themselves.