PSPP Environmental variables

[James]

We are currently trying to get pspp up and running on one of our
systems.  One thing we can't seem to figure out is where/how to set the
ENV variables to get pspp to pick them up.  I have been searching the
documentation and the internet in general for a day now, and can't seem
to come up with an answer.

We are specifically trying to set TMPDIR=/data/tmp instead of /tmp. 
Despite the variable being exported and being echo'd, it is not picked
up when pspp is called, and pspp defaults to /tmp.

This is bad for us, as we have a 20TB partition on /data/, but only
100GB or so on /.  This means that pspp can't be used on large files
without erroring out with the following error message.

pspp: writing to temporary file: No space left on device

When using pspp, I can see that it is writing to /tmp, not /data/tmp
when it is running:

pspp      15778     testuser    6u      REG                8,1  
71942660096    7700489 /tmp/tmpftWxyZS (deleted)