$ git clone -n https://src.fedoraproject.org/rpms/ghex.git /var/lib/mock/f42-build-side-1-3588155-46943/root/chroot_tmpdir/scmroot/ghex
Cloning into '/var/lib/mock/f42-build-side-1-3588155-46943/root/chroot_tmpdir/scmroot/ghex'...
$ git fetch origin daf76d4c16df28dbf730da2c5c429abab2432ca3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghex
 * [new ref]         daf76d4c16df28dbf730da2c5c429abab2432ca3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at daf76d4 Update to 48.alpha