$ git clone -n https://github.com/xcp-ng-rpms/python3.git /var/lib/mock/v8.3-u-pcoval2-10029-28676/root/chroot_tmpdir/scmroot/python3
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10029-28676/root/chroot_tmpdir/scmroot/python3'...
$ git fetch origin 4c8ab091bf13fa49c7f37a370af1e4a55ae09df3:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/python3
 * [new ref]         4c8ab091bf13fa49c7f37a370af1e4a55ae09df3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4c8ab09 bump release for test build