I think it might be safer to check whether the path already exists *and* if it's already a symlink to the right location. We should probably be failing if it exists but it's a copy (or pointed to the wrong place entirely).

If it's a copy, it's almost guaranteed to be an unnoticed bundle, which is not acceptable. If it's pointing to the wrong place, that might imply that it's either incorrect or that there are two modules with the same name that do different things. In either case, having this fail would force the packager to correct the issue.