$ git clone -n https://src.fedoraproject.org/rpms/glibc.git /var/lib/mock/f40-build-775877-128477/root/chroot_tmpdir/scmroot/glibc
Cloning into '/var/lib/mock/f40-build-775877-128477/root/chroot_tmpdir/scmroot/glibc'...
$ git fetch origin 0bd93c5697bc60e4f4a84f5b55c98f351883e689:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/glibc
 * [new ref]         0bd93c5697bc60e4f4a84f5b55c98f351883e689 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0bd93c5 Add noarch sysroot subpackages