$ git clone -n https://src.fedoraproject.org/rpms/golang-github-google-s2a.git /var/lib/mock/f39-build-1863509-42526/root/chroot_tmpdir/scmroot/golang-github-google-s2a
Cloning into '/var/lib/mock/f39-build-1863509-42526/root/chroot_tmpdir/scmroot/golang-github-google-s2a'...
$ git fetch origin 35cd67ce0a8336c5d37528ea2f13ae29940a67cd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-google-s2a
 * [new ref]         35cd67ce0a8336c5d37528ea2f13ae29940a67cd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 35cd67c Initial import