Mod_rewrite enabled?

Trying to install another instance of Omeka on lw3_dev (146.96.128.37)/library2 and get this message:

mod_rewrite is not enabled
Apache's mod_rewrite extension must be enabled for Omeka to work properly. Please enable mod_rewrite and try again.

This is message is peculiar because for a different project, I was successfully able to install Omeka on the same server:

http://library2.gc.cuny.edu/erie_canal/

Hard to say. If the Apache software was updated or modified in some way since you installed the last site some of the settings might have changed.

Regardless, mod_rewrite must be enabled in Apache for Omeka to be installed properly.

(BTW, I cannot access the site URL you sent. Is it only accessible through CUNY networks?)

yea, a development server not on the dmz.

figured it out. although i did not encounter last time on the testing server with my previous collection, it appears that when over-riding the etc/hosts file (I used /etc/hosts to simulate how the site will work in production), Omeka believes that mod_rewrite is not enabled.

So I used the machines real host name library2 rather than library and was able to install.

I would still like to find out how to modify .htacces to handle this type of scenario.

Omeka checks to see if mod_rewrite is enabled by getting a page from it self much like a browser would but it may fail to find itself if the host name you are using isn't found in the DNS system.

I was able to short circuit this by temporarily altering the file:
application/models/Installer/Requirements.php
I changed:

//We are trying to retrieve this URL.
} else if (!$modRewrite = file_get_contents($modRewriteUrl, false, $context)) {

to

//We are trying to retrieve this URL.
} else if (!$modRewrite = TRUE) {

I am installing 1.5.3 and had the mod-rewrite problem.
After trying all other recommendations on the forum, modifying the Requirements.php was the fix, and I am guessing because I am not using a direct domain name (example.org), and just the complicated address from my space on the server as the site should not yet be "public".
My question is whether when I do direct the domain name to the site if I need to change this file back and whether there are other concerns from having changed it.