The "imgui.pc.in" file results in the include path being: /usr/include/imgui/imgui but the headers are actually installed under: /usr/include/imgui The imgui path is being added on by the "includedir=..." line and then additionally in the "CFlags: ..." line. The imgui subdirectory reference should be removed from the 3rd line of the file, i.e. change includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@/imgui to includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@ Reproducible: Always
There is no package called "media-libs/imgui" in the gentoo repository. Is this a package you have installed from an overlay?
I assume you installed this from guru.
media-libs/imgui-1.87-r6 from the guru overlay
Fixed as of media-libs/imgui/imgui-1.89.9-r3