$ git clone -n https://src.fedoraproject.org/rpms/xscorch.git /var/lib/mock/f42-build-879177-181624/root/chroot_tmpdir/scmroot/xscorch
Cloning into '/var/lib/mock/f42-build-879177-181624/root/chroot_tmpdir/scmroot/xscorch'...
$ git fetch origin 3a19888d0668f2581b15d589ebdea5976b06ba28:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xscorch
 * [new ref]         3a19888d0668f2581b15d589ebdea5976b06ba28 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3a19888 Fix FTBFS