$ git clone -n https://src.fedoraproject.org/rpms/plasma-desktop.git /var/lib/mock/f42-build-3465151-45737/root/chroot_tmpdir/scmroot/plasma-desktop
Cloning into '/var/lib/mock/f42-build-3465151-45737/root/chroot_tmpdir/scmroot/plasma-desktop'...
$ git fetch origin 2a39985bd6e73b8cf5e9bcd998570fc547f24e62:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-desktop
 * [new ref]         2a39985bd6e73b8cf5e9bcd998570fc547f24e62 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2a39985 6.3.4