Re: Fix weigh dependency

[Chris Warburton]

Done some digging and it looks like these test failures only occur in
some particular circumstances. In particular, we can tincify MLSpec and
it works, or we can use a particular 0.0.3 git commit and it works, or
we can use Hackage 0.0.4 and it works. The problem may just be with
their HEAD, which we don't need to care about unless/until they release
a new official version to Hackage.