$ git clone -n https://src.fedoraproject.org/rpms/libre.git /var/lib/mock/f41-build-851970-166163/root/chroot_tmpdir/scmroot/libre
Cloning into '/var/lib/mock/f41-build-851970-166163/root/chroot_tmpdir/scmroot/libre'...
$ git fetch origin c1e6690999eccbc3b01b5d80acff02cf0e30e6e1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libre
 * [new ref]         c1e6690999eccbc3b01b5d80acff02cf0e30e6e1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c1e6690 Upgrade to 3.15.0 (#2309407)