$ git clone -n https://src.fedoraproject.org/rpms/valgrind.git /var/lib/mock/f40-build-1898230-25068/root/chroot_tmpdir/scmroot/valgrind
Cloning into '/var/lib/mock/f40-build-1898230-25068/root/chroot_tmpdir/scmroot/valgrind'...
$ git fetch origin 75b1b9147c367033bb8a44070c7944bde28d2370:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/valgrind
 * [new ref]         75b1b9147c367033bb8a44070c7944bde28d2370 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 75b1b91 3.23.0-4 - Add more upstream VALGRIND_3_23_BRANCH patches