$ git clone -n https://src.fedoraproject.org/rpms/golang-github-d5-tengo-2.git /var/lib/mock/f39-build-1442323-32451/root/chroot_tmpdir/scmroot/golang-github-d5-tengo-2
Cloning into '/var/lib/mock/f39-build-1442323-32451/root/chroot_tmpdir/scmroot/golang-github-d5-tengo-2'...
$ git fetch origin 056308d41cb3d8a6c1283c7e275abded9898599c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-d5-tengo-2
 * [new ref]         056308d41cb3d8a6c1283c7e275abded9898599c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 056308d Disable ix86