is an absolute path the build fails, due to libdir and includedir being being created by concatenating prefix and CMAKEINSTALL\, instead using CMAKE_INSTALLFULL\ which check if CMAKEINSTALL\ is an absolute path and if not concatenates it with CMAKE_INSTALL_PREFIX.
I encountered this issue while packing AviSynthPlus for nixpkgs.
When CMAKEINSTALL\
I encountered this issue while packing AviSynthPlus for nixpkgs.