$ git clone -n https://src.fedoraproject.org/rpms/kwin.git /var/lib/mock/f41-build-823921-153914/root/chroot_tmpdir/scmroot/kwin
Cloning into '/var/lib/mock/f41-build-823921-153914/root/chroot_tmpdir/scmroot/kwin'...
$ git fetch origin 6396447c46540280256ee1e781333486e3b5ad6c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kwin
 * [new ref]         6396447c46540280256ee1e781333486e3b5ad6c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6396447 rebuild