handlerURL returns 404 not found on apache2.4

[John G Heim]

I am trying to get shibboleth2 working on an apache2.4 server that is 
also running drupal7. I have a web app outside the drupal space that I 
need to protect. The problem is that something in drupal seems to be 
preventing the handlerURL from working. I have the handlerURL set to 
/Shibboleth.sso but if I point a browser there, I get a 404 not found 
error message. I can get the handlerURL to work by assigning an alias to 
it but then I get the dreaded GET/POST loop. This configuration gives me 
the file not found error:

<Location /Shibboleth.sso>
   SetHandler shib
   Require all granted
   AuthType None
</Location>

This config makes a URL like https://my.domain.edu/Shibboleth.sso/Status 
work but after authenticating, I get a loop:

alias /Shibboleth.sso /var/www/html
<Location /Shibboleth.sso>
   SetHandler shib
   Require all granted
   AuthType None
</Location>

I know this is an apache question but it must have come up before for 
people configuring shib on apache. I don't understand why apache needs 
an alias in order to honor the setHandler directive in a Location. And I 
am assuming that it is that alias that is somehow causing the loop.

-- 
John G. Heim; jheim at math.wisc.edu; 608-263-4189