$ git clone -n https://src.fedoraproject.org/rpms/plymouth-kcm.git /var/lib/mock/f39-build-1583890-38129/root/chroot_tmpdir/scmroot/plymouth-kcm
Cloning into '/var/lib/mock/f39-build-1583890-38129/root/chroot_tmpdir/scmroot/plymouth-kcm'...
$ git fetch origin 538b8bba90ae049fd53fe675b197558c22cc1995:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plymouth-kcm
 * [new ref]         538b8bba90ae049fd53fe675b197558c22cc1995 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 538b8bb 5.27.9