Ensure we're getting some equations from "cutoff times"

[Chris Warburton]

Before we go running 30 potentially-hour-long processes in a row, we
should make sure they're actually working.

In particular, we seem to get some '[BEGIN OUTPUT...END OUTPUT]' data in
stderr, but I haven't yet seen this get converted into equations on
stdout.

There may be a few reasons for this:

 - The equations are getting discarded, because they contain
   constructors which aren't in the sample.
 - The equations aren't getting parsed or spotted properly.
 - The pipeline is dying before the equation parser gets a chance to run
   (e.g. due to UNDEF)