$ git clone -n https://src.fedoraproject.org/rpms/jctools.git /var/lib/mock/f40-build-2172108-51046/root/chroot_tmpdir/scmroot/jctools
Cloning into '/var/lib/mock/f40-build-2172108-51046/root/chroot_tmpdir/scmroot/jctools'...
$ git fetch origin 0c2fee176a44fc2bcc0c2712e87e9548c2a8c0f5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jctools
 * [new ref]         0c2fee176a44fc2bcc0c2712e87e9548c2a8c0f5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0c2fee1 Update javapackages test plan to f40