Just to be clear, whenever a tool's <stdio> rules are triggered
there should be messages prepended to stdout and/or stderr.
If a tool defines a <stdio> regular expression and the regular
expression matches on stdout, a message should be prepended to
stdout. However, these will be empty if tools without <stdio>
sections fail (which is true for most tools at this time).

What you're asking for is to include the return code in the history
panel. It might make more sense to include this kind of information
in the View Details (which you get by clicking on the job name
and then clicking the "i" button). That way there's less clutter
and it's still easy to get to failures (which hopefully aren't
happening very often). What do you think?

-Scott