[hatmatrix]

In this debate there seems to be a pervasive impulse to point out "that specific problem doesn't exist anymore," and to their credit the developers are generally good at responding to serious problems.

However, the spirit of the original post was about the lack of safeguards and cohesive direction by the community to find ways to preempt such errors. It's not an easy problem to solve since Julia's composability and flexibility adds complexity not encountered in other languages. The current solution is, 'users beware', while there are a few people working on ways to enforce correct composability. I think it's best to acknowledge that this is an ongoing issue and that it's not a problem anymore because the specific ones pointed out are fixed.