$ git clone -n https://src.fedoraproject.org/rpms/centpkg.git /var/lib/mock/f40-build-1134089-20405/root/chroot_tmpdir/scmroot/centpkg
Cloning into '/var/lib/mock/f40-build-1134089-20405/root/chroot_tmpdir/scmroot/centpkg'...
$ git fetch origin a3ac5415923f430e2398c346b4e48c4686230c74:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/centpkg
 * [new ref]         a3ac5415923f430e2398c346b4e48c4686230c74 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a3ac541 Update to 0.8.6