Consensus: Tuning runtime behaviour with environment variables.

[Carlos O'Donell]

On 05/29/2013 12:25 PM, Stephan Bergmann wrote:
> (The example of LD_LIBRARY_PATH also indicates that what is required
> is not always functionality to clear the env, but sometimes it is
> functionality to reset an env back to a state before it got
> overridden.)

Your description sounds more like a broken test setup than anything
that should impact the use of env vars for tuning runtime behaviour.

The problem with LD_LIBRARY_PATH is that it changes program semantics,
and therefore has to be carefully carried into all the places that 
need it (really a fault of the test system for not modelling invocation
of AUT as a shell+env+command+args+files).

The tuning write up forbids changes to semantics, so LD_LIBRARY_APATH-
like env vars would not have been accepted.

> It's fun like that which prompts me to point out that general problem
> with env vars.  But for your specific question, I fear I need to
> chicken out.  I see both the pros and the cons, and I'm not sure what
> an ideal solution would look like,

OK, putting down an abstain.

Cheers,
Carlos.