[CMake] Fails to pass LDFLAGS with system sdbus-cpp

[jbeich]

Affects FreeBSD and other BSDs. Not sure why Nix isn't affected given it uses different prefix for each package. To reproduce install sdbus-cpp outside of /usr and /usr/local thus not part of default C compiler search path.

$ git clone https://github.com/Kistler-Group/sdbus-cpp
$ cd sdbus-cpp
$ cmake -DCMAKE_INSTALL_PREFIX:PATH=/tmp/sdbus-cpp_prefix -B /tmp/sdbus-cpp_build -G Ninja
$ cmake --build /tmp/sdbus-cpp_build
$ cmake --install /tmp/sdbus-cpp_build
$ export PKG_CONFIG_PATH=/tmp/sdbus-cpp_prefix/lib/pkgconfig

$ git clone https://github.com/hyprwm/xdg-desktop-portal-hyprland
$ cd xdg-desktop-portal-hyprland
$ cmake -DCMAKE_INSTALL_PREFIX:PATH=/tmp/xdg-desktop-portal-hyprland_prefix -B /tmp/xdg-desktop-portal-hyprland_build -G Ninja
$ cmake --build /tmp/xdg-desktop-portal-hyprland_build
[...]
ld: error: unable to find library -lsdbus-c++

$ pkg-config --libs-only-L sdbus-c++
-L/tmp/sdbus-cpp_prefix/lib

Looks like target_link_libraries uses plain sdbus-c++ instead of the imported target: https://github.com/hyprwm/xdg-desktop-portal-hyprland/blob/c0b606460a099efdea48347aeb40b01af3d9af1c/CMakeLists.txt#L45 https://github.com/hyprwm/xdg-desktop-portal-hyprland/blob/c0b606460a099efdea48347aeb40b01af3d9af1c/CMakeLists.txt#L61

[fufexan]

Yes, did that so that even if it's not found through pkg-config, we can still add it through the subproject. Should I try adding it conditionally with SDBUS using if?

[jbeich]

Why not add_library(PkgConifg::SDBUS ALIAS sdbus-c++) under if(NOT SDBUS_FOUND)?

[fufexan]

Didn't know about that, thanks! I'll add it now.

[fufexan]

https://github.com/hyprwm/xdg-desktop-portal-hyprland/commit/df8c154f5793e71796e76004812f2a03eba67e88 seems to work on Nix, I hope it also works for you.

[jbeich]

I confirm, builds fine.