InteractiveUtils crashed on CI

[Keno]

https://buildkite.com/julialang/julia-master/builds/11964#6454de35-bceb-4fdb-b92c-6f6acd92e377

An rr trace is available.

[DilumAluthge]

@Keno Is that the right link? That link doesn't have an rr trace attached, because rr failed to cleanup within 1 hour, so we SIGKILLed it.

[Keno]

@Keno Is that the right link? That link doesn't have an rr trace attached, because rr failed to cleanup within 1 hour, so we SIGKILLed it.

Oh, you are correct. My bad. Do we know what that happens?

[DilumAluthge]

Yeah I have no idea what the cause is. It's not uncommon to see.

Basically it means that rr didn't exit within 60 minutes after we sent it SIGTERM.

[Keno]

Can we see if we can reproduce this locally. Basically throw unsafe_load(Ptr{Int}(1)) in a few places in the tests and see if we can get this to happen? We may need to more aggressively send SIGTERM to the entire process tree rather than just the toplevel rr.

[vtjnash]

This was introduced by #44548, which was merged earlier that week, and changed the Julia definition of struct without changing the C representation. Sometimes that means we do an OOB value and use that to do an OOB read on an array.