Shibboleth SP Apache module sharing attributes with another apache module

[cneberg]

Whats the correct way of accessing shibboleth SP attributes in apache
from another apache module in the same instance without using headers?
 It appears env variables aren't populated until the fix_up stage, so
if you have your own "require blah" logic it runs too early to get
environment variables and you have to use headers.

Thanks,
Christopher