It’s The Environment, Stupid

The title for this weeks article is a snowclone of the phrase It’s The Economy, Stupid., a phrase that was coined during Bill Clinton’s election campaign and has come to be repeated in popular culture with the word “economy” substituted for another word.  It is a phrase that enters my head when I take something that I know works, move it or change it in some way to use something new, and then hit an initially baffling error.

In such circumstances it is typically because an environment variable is not set correctly.  The saying “It’s The Environment, Stupid” helps make me make sure that I check that Environment Variables have the value I expect them to be.  The risque nature of the phrase helping it stick in my mind and execute some steps quickly to compare environments before I go off down the wrong path.

It also comes into my thought process when I see a support issue when the user says that their programs works in one environment and not the other, and I can typically get them on the right track by checking environment variables.

I hit such an error recently.  I was looking at some new functionality in v5 of Genero Report Writer.  In my configuration to test using GDC I had checked the appropriate Environment Set to set GREDIR at a 5.00 Genero Report Writer installation, but I had not checked the same Environment Set in my configuration to test using a Browser.  As a result I got a runtime error when running a program in a Browser when I knew that program worked in the GDC…

The key debug technique is to have the ability to execute the following command (or your Operating Systems equivalent) …

RUN "env | sort > /tmp/yourname.env"

… in both the system that works and the system that does not work, and to then do a diff or compare the output of the two files.  This will typically tell you that an environment variable has a different value or is missing.

In my case, this technique gave me output of …