$ git clone -n https://src.fedoraproject.org/rpms/gvfs.git /var/lib/mock/f42-build-3426560-45185/root/chroot_tmpdir/scmroot/gvfs
Cloning into '/var/lib/mock/f42-build-3426560-45185/root/chroot_tmpdir/scmroot/gvfs'...
$ git fetch origin facf321ed6257a5fcfd3e1b4b6a1e4fd16d2a671:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gvfs
 * [new ref]         facf321ed6257a5fcfd3e1b4b6a1e4fd16d2a671 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at facf321 Add support for libnfs 6