$ git clone -n https://src.fedoraproject.org/rpms/clang.git /var/lib/mock/f41-build-1297782-23396/root/chroot_tmpdir/scmroot/clang
Cloning into '/var/lib/mock/f41-build-1297782-23396/root/chroot_tmpdir/scmroot/clang'...
$ git fetch origin 36e4571e31366e2f09739123565466aef0988840:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/clang
 * [new ref]         36e4571e31366e2f09739123565466aef0988840 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 36e4571 18.1.7 Release