Rails App freezes when accessed

Hi All,

I just had this problem come up today and so far I'm stumped. This
morning, my mongrels were all completely unresponsive. I had to kill
-9 them to get them to go away. I restarted them, but the first time
that they were accessed they froze again. Nothing gets printed to the
logs. I tried starting a single mongrel and accessing it directly.
If I hit CTRL-C before accessing it, it will kill the server. If I
try to connect to it, the browser just hangs and CTRL-C no longer
kills the server. I have to kill -9 it. I then tried starting the
app with Webrick, but I get the exact same behavior, so it's not
anything to do with mongrel. This is on a fully-patched CentOS 5
server. I updated all of my gems to the latest versions (including
rails and mongrel), but it didn't make any difference. Nothing at all
is being printed to production.log or mongrel.log. Nothing gets
printed to the console when I run the single server other than the
standard startup stuff. Nothing shows up past "Use CTRL-C to stop."

I tried running my app on my Mac and there is no problem. It comes
right up and is accessible. It's just on the production server that I
have issues. Has anyone seen this before? Any suggestions? I tried
to find a way to turn on debugging, but I didn't see anything
obvious. If there is a way, let me know and I'll give that a try.

Thanks!
--Jason

I managed to get debugging working and I now get this output:

Exception `TypeError' at /usr/lib64/ruby/gems/1.8/gems/
activesupport-2.0.2/lib/active_support/core_ext/class/
inheritable_attributes.rb:131 - can't dup TrueClass
/usr/lib64/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
base.rb:426: warning: instance variable @view_paths not initialized
/usr/lib64/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/
observer.rb:35: warning: instance variable @observers not initialized
Exception `TypeError' at /usr/lib64/ruby/gems/1.8/gems/
activesupport-2.0.2/lib/active_support/core_ext/class/
inheritable_attributes.rb:131 - can't dup TrueClass
/usr/lib64/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
base.rb:426: warning: instance variable @view_paths not initialized
/usr/lib64/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
base.rb:426: warning: instance variable @view_paths not initialized
/usr/lib64/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
base.rb:645: warning: instance variable @template not initialized
/usr/lib64/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
base.rb:426: warning: instance variable @view_paths not initialized
/usr/lib64/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
base.rb:426: warning: instance variable @view_paths not initialized

I assume the error has something to do with the TypeError exception.
The line that is causing it is this:

memo.update(key => (value.dup rescue value))

Unfortunately, the method that contains it is a little beyond my
understanding.

Thanks!
--Jason