Thanks for pointing to this. I remember reading about it a while back, but when I needed a stack trace wrapper I couldn't remember the name. I ended up adding a function to an error library I maintain (github.com/surullabs/fault).

When I find some time I'll pull out my code and start using either errgo or the SpaceMonkey version.

worth pointing out github.com/spacemonkeygo/errors is 100% compatible, allows you to get a source and explanation, allows for error hierarchies, allows for arbitrary user-defined error details, etc.