$ git clone -n https://src.fedoraproject.org/rpms/vfrnav.git /var/lib/mock/f42-build-862969-171273/root/chroot_tmpdir/scmroot/vfrnav
Cloning into '/var/lib/mock/f42-build-862969-171273/root/chroot_tmpdir/scmroot/vfrnav'...
$ git fetch origin 1967cb71b47330f34f06ccd880c3962c87c534a3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vfrnav
 * [new ref]         1967cb71b47330f34f06ccd880c3962c87c534a3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1967cb7 Rebuild (gdal)