puppetlabs/puppetlabs-stdlib — pull request #179 by lmello (2013-09-09 14:09:23+00:00)
Title: enhanced the error message of pick function.

When pick function fail return a better error message like
the other stdlib functions, indicating that the error
is on function pick.

This would help people that see the error to identity it is
related to a incorrect use of stdlib function pick, instead of having
to grep all puppet libraries and manifests source for the old message.

I had also changed the spec test.