response.SetError(...) returns "panic: Message can't be modified"

[tleyden]

As mentioned in #20 (comment), there is still some loose ends from #20 in terms of propagating the error back to the other side.

I'm spinning this off to a separate ticket since #20 was approved, and I think it's an incremental improvement over the existing situation.

[tleyden]

@snej can you take a look at #20 (comment) and let me know?

[tleyden]

From @snej in the PR this was spun out of:

It doesn't affect the peer (since the socket's already been closed). It's for the benefit of the code using go-blip, i.e. SG -- it fulfills the promise that the request it sent will get a response. This helps it clean up properly.

[snej]

Any ideas on how to mark the response as having run into an error?

You can't do it from the outside because response messages are immutable in the API. You should probably add a new internal method to Message that tells it to become an error.