Improved error messages is great. But one area specifically that is in desperate need of some love is the type errors from Dialyzer. They are rarely helpful to identify what is actually wrong in the code. Typically the error message will point to something several layers up or down in the call stack and prints out a huge blob of unreadable and unhelpful type signatures. Most of the time the best you can do is to simply compile and run the system to figure out what is wrong with the types. The obscurity of the type errors remind me of C++ template errors.