My question is this:

I have a Cygwin shell script which sets an environment variable called
"REVISION" (set to "anotherversion").

My .wxs has the following code in it:

    <?define BUILD=none?>

    <!-- Override BUILD if the environment variable REVISION is preset
-->
    <?ifdef $(env.REVISION) ?>
        <?define BUILD=$(env.REVISION) ?>
    <?endif?>

I know the variable exists, but Candle doesn't seem to pick it up.

The idea is that BUILD should be set to anotherversion.

Has anyone else tried to run WiX in this way?  My job needs this, so
any tips are welcome!
I've had zero success exploring the usual avenues (Google, FAQs,
etc.).

I'm also new to XML, is there a way that I can show the incoming env.
vars from within my .wxs file?

Thanks to all.

GLK