$ git clone -n https://src.fedoraproject.org/rpms/glibc.git /var/lib/mock/f42-build-side-1-3534669-46551/root/chroot_tmpdir/scmroot/glibc
Cloning into '/var/lib/mock/f42-build-side-1-3534669-46551/root/chroot_tmpdir/scmroot/glibc'...
$ git fetch origin d2ae0e3b919a3c9650cc604af23bb6e9ff97e598:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/glibc
 * [new ref]         d2ae0e3b919a3c9650cc604af23bb6e9ff97e598 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d2ae0e3 Replace stale files in /usr/sbin with symlinks on unmerged systems