$ git clone -n https://src.fedoraproject.org/rpms/glibc.git /var/lib/mock/f40-build-2236096-53493/root/chroot_tmpdir/scmroot/glibc
Cloning into '/var/lib/mock/f40-build-2236096-53493/root/chroot_tmpdir/scmroot/glibc'...
$ git fetch origin d6f60005eb62ac0f1614e96f76281f719b214ba8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/glibc
 * [new ref]         d6f60005eb62ac0f1614e96f76281f719b214ba8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d6f6000 Infinite loop in res_mkquery with malformed domain name (#2255506)