joyent/node — comment on commit 6ee73a2fee78eeda8eb5d171dbf0b9d13ce54119
File: src/node.cc line 808
By bnoordhuis:

That's what annoys me about `ErrnoException()` - if you want to provide a path but not an error message, you need to pass in an empty string. It's counter-intuitive, easy to forget.