[microcolonel]

One other one is that it has hilariously poor performance, and bizarre failure cases. For some forms of network failures it'll just say "callback called too many times" and crash.

There are literally no worse major package managers.

A good package manager can be misused and still work reasonably well; a bad one doesn't even work all that well when used correctly.

[int_19h]

Or how about this for error reporting:

https://github.com/npm/npm/issues/9633

I especially like the part where it says "This is most likely not a problem with npm itself", even though it clearly is a problem with npm itself (as evidenced by non-deterministic nature of the bug).

[abritinthebay]

That message is their generic message because ANY error ended up being reported in github as an issue with NPM.

Again, bad dev practice.