$ git clone -n https://src.fedoraproject.org/rpms/valgrind.git /var/lib/mock/f42-bootstrap-3462985-45594/root/chroot_tmpdir/scmroot/valgrind
Cloning into '/var/lib/mock/f42-bootstrap-3462985-45594/root/chroot_tmpdir/scmroot/valgrind'...
$ git fetch origin f62b81aaa2944ce415203ea931d90969d07687d1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/valgrind
 * [new ref]         f62b81aaa2944ce415203ea931d90969d07687d1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f62b81a 3.24.0-8