$ git clone -n https://src.fedoraproject.org/rpms/boost.git /var/lib/mock/f42-build-3181973-40950/root/chroot_tmpdir/scmroot/boost
Cloning into '/var/lib/mock/f42-build-3181973-40950/root/chroot_tmpdir/scmroot/boost'...
$ git fetch origin bd0476d632fbe90d4bab658555498bc5d0c4f769:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/boost
 * [new ref]         bd0476d632fbe90d4bab658555498bc5d0c4f769 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bd0476d Fix no member named ‘that’ error