$ git clone -n https://src.fedoraproject.org/rpms/plymouth-kcm.git /var/lib/mock/f40-build-2476685-61590/root/chroot_tmpdir/scmroot/plymouth-kcm
Cloning into '/var/lib/mock/f40-build-2476685-61590/root/chroot_tmpdir/scmroot/plymouth-kcm'...
$ git fetch origin df9ec55bff1c9e4d37b40009ca06acc4d445abc4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plymouth-kcm
 * [new ref]         df9ec55bff1c9e4d37b40009ca06acc4d445abc4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at df9ec55 6.0.0