$ git clone -n https://src.fedoraproject.org/rpms/golang-github-mdlayher-packet.git /var/lib/mock/f40-build-1300807-23426/root/chroot_tmpdir/scmroot/golang-github-mdlayher-packet
Cloning into '/var/lib/mock/f40-build-1300807-23426/root/chroot_tmpdir/scmroot/golang-github-mdlayher-packet'...
$ git fetch origin d366b363235a8af88ac8ef85875765725627ee2c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-mdlayher-packet
 * [new ref]         d366b363235a8af88ac8ef85875765725627ee2c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d366b36 Initial import; Fixes: RHBZ#2260164