$ git clone -n https://src.fedoraproject.org/rpms/plymouth.git /var/lib/mock/f42-build-side-1-3582435-46884/root/chroot_tmpdir/scmroot/plymouth
Cloning into '/var/lib/mock/f42-build-side-1-3582435-46884/root/chroot_tmpdir/scmroot/plymouth'...
$ git fetch origin e557f357478374dddf6d67a41724f7949a5e84b6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plymouth
 * [new ref]         e557f357478374dddf6d67a41724f7949a5e84b6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e557f35 Don't use simpledrm together with LUKS (rhbz#2359283, rhbz#2339072)