Mac OS X 10.1 and Web Sharing failure: the solution

We have several reports of readers unable to use Web Sharing after updating to OS X 10.1. Console returns the error: dyld: /usr/sbin/httpd Undefined symbols: _apple_hfs_module /usr/sbin/apachectl start: httpd could not be started.

A description of and solution to the problem is included on this stepwise.com page. It states:

"If you haven't installed the WebSharing update, then you're probably not effected. As part of the WebSharing update Apple included the mod_hfs_Apple module which helps to prevent some of the security issues related to HFS case insensitivity. To enable this, there were two lines added to your /etc/httpd/httpd.conf file. However, in 10.1, Apple changed the name by which they reference the module, but not the file name. The updater doesn't change this line in your httpd.conf file. So, we'll need to do that ourselves to fix this problem. You need to search for the instance of apple_hfs_module and replace it with hfs_apple_module." Use: <sudo perl -i.prefix -p -e 's/apple_hfs_module/hfs_apple_module/g' /etc/httpd/httpd.conf> in Terminal.

Note: The web page discusses several other "gotchas" including the wget vs. curl command line tool previously covered here.

James Sentman offered a similar analysis of the problem with a somewhat different solution. But the stepwise one is the simplest, so we would go with that.