$ git clone -n https://src.fedoraproject.org/rpms/genext2fs.git /var/lib/mock/f45-build-9716-408/root/chroot_tmpdir/scmroot/genext2fs
Cloning into '/var/lib/mock/f45-build-9716-408/root/chroot_tmpdir/scmroot/genext2fs'...
$ git fetch origin 51f530d00161d20fd3e8b2287284c20bc9e001df:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/genext2fs
 * [new ref]         51f530d00161d20fd3e8b2287284c20bc9e001df -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 51f530d Update to 1.6.3