$ git clone -n https://src.fedoraproject.org/rpms/bsf.git /var/lib/mock/f42-build-3346789-45002/root/chroot_tmpdir/scmroot/bsf
Cloning into '/var/lib/mock/f42-build-3346789-45002/root/chroot_tmpdir/scmroot/bsf'...
$ git fetch origin d745ce43910b2ad28a6d24a4186b5eebd517d5fe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bsf
 * [new ref]         d745ce43910b2ad28a6d24a4186b5eebd517d5fe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d745ce4 Remove javadoc subpackage