[tedunangst]

Why is it a bug? I write a program to download four files. I do so in parallel. Sometimes X finishes first, sometimes Y finishes first, and the files are written to disk in a different order. Why do I want to serialize this operation?

[rbanffy]

The end result is a set of four files. You don't care about the order they are laid out on the disk and the next steps shouldn't let the order of those files influence the end result.

Let's assume there is a latent bug in the compiler that gets triggered if file four is the first one. Good luck debugging that.

[tedunangst]

But parent claimed that creating a set with a different order was inherently a bug. Not that depending on the order of an unordered set was a bug.

[anth_anm]

It's the internal structure of the files.