$ git clone -n https://src.fedoraproject.org/rpms/diffoscope.git /var/lib/mock/f38-build-side-42-init-devel-1282414-30671/root/chroot_tmpdir/scmroot/diffoscope
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1282414-30671/root/chroot_tmpdir/scmroot/diffoscope'...
$ git fetch origin 707af0e8835748e3ab8f336db8906d9b85a7e1cc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/diffoscope
 * [new ref]         707af0e8835748e3ab8f336db8906d9b85a7e1cc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 707af0e Skip tests that fail with latest ImageMagick