[vsgherzi]

I can only imagine that

1. it’s to performance sensitive

Or

2. The os is so darn large it’s hard to recompile everything

[kenferry]

I worked at Apple for a long time. The OS gets fully recompiled regularly.

A simultaneous total world build is relatively rare (is that needed here?), but it does happen. Sometimes new compiler versions or features need this.

[vsgherzi]

Hm that leaves more questions for me. Why does this path not have bounds checking, is think perhaps a limit of the clang flag or is it more simply a mistake of omission on apples part. Either way it seems like a bad look. I wish we’d get a post mortem

[asimovDev]

I dunno if that's sensitive information, but how long did a build usually take?

[kenferry]

I wasn't close enough to that to know how long a world build took. Didn't seem like it was too crazy though. Incremental (non-world) builds of the OS come out every day.