$ git clone -n https://src.fedoraproject.org/rpms/libXfixes.git /var/lib/mock/f45-build-15758-479/root/chroot_tmpdir/scmroot/libXfixes
Cloning into '/var/lib/mock/f45-build-15758-479/root/chroot_tmpdir/scmroot/libXfixes'...
$ git fetch origin 88ddb80cc358e3ba5a255e5c5e9c20ba473d9cb0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libXfixes
 * [new ref]         88ddb80cc358e3ba5a255e5c5e9c20ba473d9cb0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 88ddb80 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild