Handle piped failures properly

[beauraines]

set -o pipefail

OR

check $PIPESTATUS in the rcCheck function...

https://unix.stackexchange.com/questions/14270/get-exit-status-of-process-thats-piped-to-another

But I've had a problem making the latter work on OS X

[beauraines]

Works great on linux, though ¯_(ツ)_/¯