$ git clone -n https://src.fedoraproject.org/rpms/plymouth-kcm.git /var/lib/mock/f40-build-2173929-51063/root/chroot_tmpdir/scmroot/plymouth-kcm
Cloning into '/var/lib/mock/f40-build-2173929-51063/root/chroot_tmpdir/scmroot/plymouth-kcm'...
$ git fetch origin d5effbbad297a70c8057071d461e9a7e8bbcfda0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plymouth-kcm
 * [new ref]         d5effbbad297a70c8057071d461e9a7e8bbcfda0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d5effbb 5.91.0