Unexplained linking errors if you forget to clone the submodules

[sfan5]

%%% meson build
The Meson build system
Version: 1.3.0
Source dir: /tmp/libplacebo
Build dir: /tmp/libplacebo/build
Build type: native build
Project name: libplacebo
Project version: 7.342.0
C compiler for the host machine: cc (gcc 13.2.1 "cc (GCC) 13.2.1 20230801")
C linker for the host machine: cc ld.bfd 2.41.0
C++ compiler for the host machine: c++ (gcc 13.2.1 "c++ (GCC) 13.2.1 20230801")
C++ linker for the host machine: c++ ld.bfd 2.41.0
Host machine cpu family: x86_64
Host machine cpu: x86_64
Compiler for C supports arguments -Wincompatible-pointer-types: YES 
Compiler for C supports link arguments -Wl,--exclude-libs=ALL: YES 
Library m found: YES
Program python3 found: YES (/usr/bin/python)
Run-time dependency threads found: YES
Header "pthread.h" has symbol "pthread_condattr_setclock" with dependency threads: YES 
Found pkg-config: YES (/usr/bin/pkg-config) 2.1.0
Run-time dependency libunwind found: YES 1.7.2
Library execinfo found: NO
Checking for function "backtrace_symbols" with dependency -lexecinfo: YES 
Check usable header "dbghelp.h" : NO 
Library dl found: YES
Fetching value of define "__MINGW32__" : (undefined) 
Run-time dependency shaderc found: YES 2023.7.1
Message: Skipping `glslang` because `shaderc` is available
Check usable header "d3d11.h" : NO 
Check usable header "d3d11_4.h" : NO 
Check usable header "dxgi1_6.h" : NO 
Found CMake: /usr/bin/cmake (3.28.1)
Run-time dependency spirv-cross-c-shared found: NO (tried pkgconfig and cmake)
Library version found: NO
Library dl found: YES
Run-time dependency vulkan found: YES 1.3.274
Header "vulkan/vulkan_core.h" has symbol "VK_VERSION_1_3" with dependency vulkan: YES 
Run-time dependency lcms2 found: YES 2.16
Run-time dependency dovi found: YES 3.2.0
Run-time dependency libxxhash found: YES 0.8.2
Configuring config.h using configuration
Configuring config_internal.h using configuration
WARNING: Library target 'placebo' has 'name_prefix' set. Compilers may not find it from its '-lplacebo' linker flag in the 'libplacebo.pc' pkg-config file.
WARNING: Library target 'placebo' has 'name_prefix' set. Compilers may not find it from its '-lplacebo' linker flag in the 'libplacebo-uninstalled.pc' pkg-config file.
Run-time dependency glfw3 found: NO (tried pkgconfig and cmake)
Run-time dependency sdl2 found: YES 2.28.5
Run-time dependency sdl2_image found: YES 2.8.1
Run-time dependency libavcodec found: YES 60.31.102
Run-time dependency libavformat found: YES 60.16.100
Run-time dependency libavutil found: YES 58.29.100
Has header "nuklear.h" : NO 
demos/meson.build:31: WARNING: Nuklear was not found in `demos/3rdparty`. Please run `git submodule update --init` followed by `meson --wipe`.
Check usable header "EGL/egl.h" : YES 
Configuring config_demos.h using configuration
Build targets in project: 24

libplacebo 7.342.0

  Optional features
    d3d11       : NO
    dovi        : YES
    gl-proc-addr: YES
    glslang     : NO
    lcms        : YES
    libdovi     : YES
    opengl      : YES
    shaderc     : YES
    vk-proc-addr: YES
    vulkan      : YES
    xxhash      : YES

Found ninja-1.11.1 at /usr/bin/ninja
WARNING: Running the setup command as `meson [options]` instead of `meson setup [options]` is ambiguous and deprecated.
%%% ninja -C ./build
ninja: Entering directory `./build'
[23/95] Generating src/vulkan/utils_gen.c with a custom command (wrapped by meson to set env)
Found vk.xml: /usr/share/vulkan/registry/vk.xml
[32/95] Generating src/opengl/include/glad/gl.h with a custom command (wrapped by meson to set env)
[21.12.2023 16:54:35][DEBUG	][glad.plugin	]: loaded language c: <class 'glad.generator.c.__init__.CGenerator'>
[21.12.2023 16:54:35][DEBUG	][glad.plugin	]: loaded language rust: <class 'glad.generator.rust.__init__.RustGenerator'>
[21.12.2023 16:54:35][DEBUG	][glad.plugin	]: loaded specification egl: <class 'glad.specification.EGL'>
[21.12.2023 16:54:35][DEBUG	][glad.plugin	]: loaded specification gl: <class 'glad.specification.GL'>
[21.12.2023 16:54:35][DEBUG	][glad.plugin	]: loaded specification glx: <class 'glad.specification.GLX'>
[21.12.2023 16:54:35][DEBUG	][glad.plugin	]: loaded specification vk: <class 'glad.specification.VK'>
[21.12.2023 16:54:35][DEBUG	][glad.plugin	]: loaded specification wgl: <class 'glad.specification.WGL'>
[21.12.2023 16:54:35][INFO	][glad   	]: getting 'gl' specification from remote location
[21.12.2023 16:54:35][DEBUG	][glad.files	]: intercepted attempt to retrieve resource: 'https://raw.githubusercontent.com/KhronosGroup/OpenGL-Registry/main/xml/gl.xml'
[21.12.2023 16:54:35][INFO	][glad.files	]: opening packaged resource: 'gl.xml'
[21.12.2023 16:54:35][INFO	][glad   	]: getting 'egl' specification from remote location
[21.12.2023 16:54:35][DEBUG	][glad.files	]: intercepted attempt to retrieve resource: 'https://raw.githubusercontent.com/KhronosGroup/EGL-Registry/main/api/egl.xml'
[21.12.2023 16:54:35][INFO	][glad.files	]: opening packaged resource: 'egl.xml'
[21.12.2023 16:54:35][INFO	][glad   	]: generating gl:core/gl=None
[21.12.2023 16:54:35][INFO	][glad   	]: no explicit version given for api gl, using Version(major=4, minor=6)
[21.12.2023 16:54:35][INFO	][glad   	]: generating gles2:None/gl=None
[21.12.2023 16:54:35][INFO	][glad   	]: no explicit version given for api gles2, using Version(major=3, minor=2)
[21.12.2023 16:54:35][INFO	][glad   	]: merging [FeatureSet(name=gl, info=[gl:core=4.6], extensions=21), FeatureSet(name=gles2, info=[gles2=3.2], extensions=10)]
[21.12.2023 16:54:35][INFO	][glad   	]: merged into FeatureSet(name=gl, info=[gl:core=4.6, gles2=3.2], extensions=29)
[21.12.2023 16:54:35][INFO	][glad   	]: generating feature set FeatureSet(name=gl, info=[gl:core=4.6, gles2=3.2], extensions=29)
[21.12.2023 16:54:35][DEBUG	][glad.files	]: intercepted attempt to retrieve resource: 'https://raw.githubusercontent.com/KhronosGroup/EGL-Registry/main/api/KHR/khrplatform.h'
[21.12.2023 16:54:35][INFO	][glad.files	]: opening packaged resource: 'khrplatform.h'
[21.12.2023 16:54:35][INFO	][glad   	]: generating egl:None/egl=None
[21.12.2023 16:54:35][INFO	][glad   	]: no explicit version given for api egl, using Version(major=1, minor=5)
[21.12.2023 16:54:35][INFO	][glad   	]: merging [FeatureSet(name=egl, info=[egl=1.5], extensions=7)]
[21.12.2023 16:54:35][INFO	][glad   	]: merged into FeatureSet(name=egl, info=[egl=1.5], extensions=7)
[21.12.2023 16:54:35][INFO	][glad   	]: generating feature set FeatureSet(name=egl, info=[egl=1.5], extensions=7)
[21.12.2023 16:54:35][DEBUG	][glad.files	]: intercepted attempt to retrieve resource: 'https://raw.githubusercontent.com/KhronosGroup/EGL-Registry/main/api/EGL/eglplatform.h'
[21.12.2023 16:54:35][INFO	][glad.files	]: opening packaged resource: 'eglplatform.h'
[58/95] Compiling C object src/libplacebo.so.342.p/glsl_spirv_shaderc.c.o
[...]
[95/95] Linking target demos/plplay
FAILED: demos/plplay 
c++  -o demos/plplay demos/plplay.p/plplay.c.o demos/plplay.p/settings.c.o demos/plplay.p/window.c.o demos/plplay.p/utils.c.o -Wl,--as-needed -Wl,--no-undefined -Wl,--exclude-libs=ALL '-Wl,-rpath,$ORIGIN/../src' -Wl,-rpath-link,/tmp/libplacebo/build/src -Wl,--start-group demos/libsdl-vk.a src/libplacebo.so.342 demos/libsdl-gl.a -lm -pthread /usr/lib/libunwind.so -ldl /usr/lib/libshaderc_shared.so /usr/lib/libvulkan.so /usr/lib/liblcms2.so /usr/lib/libdovi.so /usr/lib/libavcodec.so /usr/lib/libavformat.so /usr/lib/libavutil.so /usr/lib/libSDL2.so -Wl,--end-group
/usr/bin/ld: demos/plplay.p/plplay.c.o: in function `main':
/tmp/libplacebo/build/../demos/plplay.c:669:(.text.startup+0x7e): undefined reference to `parse_args'
collect2: Fehler: ld gab 1 als Ende-Status zurück
ninja: build stopped: subcommand failed.

[sfan5]

Apparently I forgot to clone recursively but this should still be detected earlier IMO.

[eli-schwartz]

If you wrap each submodule as a meson subproject then meson will enforce their presence and download it on demand... :)