RewriteCond with SetEnv

Question

In my .htaccess I set:

SetEnv APPLICATION_ENV development

And I want to check if APPLICATION_ENV equals dev

Answer 1

Since I had to test this myself and could only confirm that what you wrote was correct, I started to look around and found this post regarding SetEnv, SetEnvIf and RewriteRule visibility. It looks like SetEnv is not visible for RewriteCond and if I change your example to use:

SetEnvIf APPLICATION_ENV  ^(.*)$ APPLICATION_ENV=development

I actually get the rules you have to load app_dev.php. You could set the variable using RewriteRule as well:

RewriteRule .* - [E=APPLICATION_ENV:development,NE]

However, looks like SetEnv can't be used (Tested on Apache 2.2.22).

EDIT
As julp pointed out in a comment to this post this is quite clear in Apache document section Setting Environment Variables:

The SetEnv directive runs late during request processing meaning that directives 
such as SetEnvIf and RewriteCond will not see the variables set with it.