As an example, with mesa-git, llvm-libs-svn and xf86-video-amdgpu-git installed, and then running trizen -S mesa llvm-libs xf86-video-amdgpu, trizen only checks the dependants of mesa before failing to install as the currently installed (and to be replaced) xf86-video-amdgpu-git requires mesa-git specifically, even though it will be uninstalled in the same command.