$ git clone -n https://src.fedoraproject.org/rpms/golang-github-labstack-gommon.git /var/lib/mock/f40-build-2254077-54223/root/chroot_tmpdir/scmroot/golang-github-labstack-gommon
Cloning into '/var/lib/mock/f40-build-2254077-54223/root/chroot_tmpdir/scmroot/golang-github-labstack-gommon'...
$ git fetch origin c40c30a3a0bf6fd50a24b807f190ead525a852e9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-labstack-gommon
 * [new ref]         c40c30a3a0bf6fd50a24b807f190ead525a852e9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c40c30a Remove deprecated %patchN syntax