An Erlang process has its own heap, so when it blows up, its state just goes away, leaving your remaining program's state untouched. With Go, there is no way to recover sanely; even if your goroutines are designed to copy memory, Go itself has a single heap.

Now, this is a very odd design decision for a language that claims it's designed for reliability. Perhaps Go's authors thinks it's better just for the entire program to die if a single goroutine falls over; well, that's one way, but it's a crude one. Erlang's design is simply better.

I wonder if Go can ever adopt per-goroutine heaps, or whether it's too late at this stage. I was happy to see that Rust has chosen to follow Erlang's design by having per-task heaps, even if all the pointer mechanics (three times of pointers, ownership transfer, reference lifecycles and so forth) result in some fairly intrusive and gnarly syntax.

Go will share memory, by default, and special attention must be taken preventing or avoiding it. It's not an allowance.

> In fact, the Go team explicitly tells you not to do that

And yet they have refused to implement a correct model, even though they have no problem imposing their view when it fits them (and having the interpreter get special status in breaking them, see generics).

Sadly, that doesn't mean what you think it means. It really means: don't organize your IPC around shared state. The juxtaposition in the second half is not directly related to the first half (except poetically), though it does do a good job of completing the their picture of CSP. Also note: it is explicitly talking about shared (sadly mutable) state.

You can always opt not to share memory, but there's no facility to prove or enforce it. It's not dire, with practice you can send values, or never mutate referenced objects. It is very natural for the most part. I've done it, but not in Go.

Finally, it's not doom. Even C can do threading after all, and somehow these things don't blow up too much. But there's value in eliminating the pitfall entirely. When people criticize Go for being imperfect, they're not saying it's not going to work, they're contrasting with a more effective solution or lamenting that some design decisions weakened the effort.