$ git clone -n https://src.fedoraproject.org/rpms/plymouth-kcm.git /var/lib/mock/f42-build-881063-183098/root/chroot_tmpdir/scmroot/plymouth-kcm
Cloning into '/var/lib/mock/f42-build-881063-183098/root/chroot_tmpdir/scmroot/plymouth-kcm'...
$ git fetch origin 6c2683fba09c477a6e4eff8383b637e1df4553e4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plymouth-kcm
 * [new ref]         6c2683fba09c477a6e4eff8383b637e1df4553e4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6c2683f 6.3.2