JuliaLang/julia — pull request #4279 by ihnorton (2013-09-14 13:09:10+00:00)
Title: Add readerr(::AbstractCmd) function to capture stderr from commands

This seems like an occasionally useful thing that should be simpler to do (undocumented now as far as I can tell, requires calling unexported Base.Pipe and Base.wait_close). I'm happy to implement any suggestions for a more elegant way to roll this in. Alternatively, how to do this should at least be documented somewhere.