[Boost-build] How to set an environmental variable for a specific test?

Subject: [Boost-build] How to set an environmental variable for a specific test?
From: Beman Dawes (bdawes_at_[hidden])
Date: 2011-06-28 10:28:53

Ticket #5289 (and several other tickets) complain that programs linking to
Boost.Filesystem fail to start on various locale related problem.

A suggested test case is to try to start a program using filesystem when the
LANG environmental variable is set to an invalid value, such as "xx_YY.UTF-8".
I've verified that on Linux this will cause a startup failure.

I'd like to include this in the regular filesystem test suite. Is it possible to
set an environmental variable for a specific "[ run whatever.cpp ]" test?

If that isn't possible, what is the fallback?

TIA,

--Beman