$ git clone -n https://src.fedoraproject.org/rpms/busybox.git /var/lib/mock/f40-build-795769-140317/root/chroot_tmpdir/scmroot/busybox
Cloning into '/var/lib/mock/f40-build-795769-140317/root/chroot_tmpdir/scmroot/busybox'...
$ git fetch origin ca207fe85b7273293eef01e6388aff3286aca855:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/busybox
 * [new ref]         ca207fe85b7273293eef01e6388aff3286aca855 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ca207fe fix build without cbq support