$ git clone -n https://src.fedoraproject.org/rpms/pixman.git /var/lib/mock/f45-build-28535-631/root/chroot_tmpdir/scmroot/pixman
Cloning into '/var/lib/mock/f45-build-28535-631/root/chroot_tmpdir/scmroot/pixman'...
$ git fetch origin bf83d145a32e97973e2cf3afb4971e8cc8cbfa99:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pixman
 * [new ref]         bf83d145a32e97973e2cf3afb4971e8cc8cbfa99 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bf83d14 drop unused patches