-DALSOFT_REQUIRE_RTKIT defaults to false[1], leaving -DALSOFT_RTKIT and HAVE_RTKIT's value floating depending on whether D-Bus is installed. D-Bus is dlopen()ed at runtime[2], so this never really results in an issue when uninstalling dbus, but it should be fixed for consistent behavior. [1]: https://github.com/kcat/openal-soft/blob/master/CMakeLists.txt#L685 [2]: https://github.com/kcat/openal-soft/blob/master/core/dbus_wrap.cpp#L19