In go1.7rc1, there's an extra line of output in each block of comments in debug=1 profiles. It has address 0x0, and does not include a function name. It seems to correspond to the runtime.goexit frame. I don't know that this is hurting anything (the data lines seem to be valid and unchanged, it's just a difference in the comments), though I also don't know the extent to which tools in the wild make use of those comment lines.
What version of Go are you using (go version)?
I see this behavior in go1.7rc1, and not in go1.6.2.
What operating system and processor architecture are you using (go env)?
What did you do?
I visually scanned a /debug/pprof/goroutine?debug=1 profile.
What did you expect to see?
I'd expect each non-comment profile line to end with an address in runtime.goexit. I'd expect to not see an associated line in the following comments.
What did you see instead?
The goroutine profile has each stack starting at an address in runtime.goexit. In go1.6.2, this stack frame doesn't get an associated comment in debug=1 profiles. In go1.7rc1, it gets a comment for the frame, showing address 0x0 and no associated symbol name.