[catnaroek]

> if you invoke undefined behavior in your program (like the Heartbleed bug for example) it doesn't matter that in the end the compiler is correct.

This is not true. It means that you can safely omit the compiler writer from the list of people to burn at the stake.

[kazinator]

> It means that you can safely omit the compiler writer from the list of people to burn at the stake.

Not if the problem is due to a compiler change which breaks something that has worked for decades and in other compilers too.

Say we have an open source distro full of programs, and a compiler change breaks some program that hasn't been touched in years so that it misbehaves in situations where old builds of that program do not.

This means the compiler writers aren't testing with a full distro, and possibly that they don't care.

"We can do anything we want within the limits set out by the ISO language spec, and that spec alone; let the downstream consumers sort out whatever happens."

[catnaroek]

> Not if the problem is due to a compiler change which breaks something that has worked for decades and in other compilers too.

The compiler writer is within their rights to perform any changes that don't contravene the language specification, whether it breaks other people's code or not.

> "We can do anything we want within the limits set out by the ISO language spec, and that spec alone; (...)"

Yes.

> "(...) let the downstream consumers sort out whatever happens."

It's the language user's responsibility to make sure they write meaningful programs.