$ git clone -n https://src.fedoraproject.org/rpms/mock.git /var/lib/mock/f41-build-side-1-2806294-32867/root/chroot_tmpdir/scmroot/mock
Cloning into '/var/lib/mock/f41-build-side-1-2806294-32867/root/chroot_tmpdir/scmroot/mock'...
$ git fetch origin a8a3c918894bf5badab264314e1b1096dbbd83ca:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mock
 * [new ref]         a8a3c918894bf5badab264314e1b1096dbbd83ca -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a8a3c91 Update mock to 5.9-1