# Deploying a Rails app: Uninitialized constant Haml::Filters::Markdown **URL:** \ **Category:** Rails\ **Created:** [September 8, 2010, 8:08am UTC](https://www.ruby-forum.com/t/deploying-a-rails-app-uninitialized-constant-haml-markdown/194633 "2010-09-08T08:08:37Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![JRJRJR](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/dc4da7/32.png) [@JRJRJR](https://www.ruby-forum.com/u/JRJRJR)\ **Post date:** [September 8, 2010, 8:08am UTC](https://www.ruby-forum.com/t/deploying-a-rails-app-uninitialized-constant-haml-markdown/194633/1 "2010-09-08T08:08:37Z")
Hello all, I already posted this question on [stackoverflow.com](http://stackoverflow.com), but I figured there would be more people that could help me here, so I’m posting to this list as well. I am in the process of deploying a Rails application (that works fine in development) to a new production server running Apache and Passenger (with Ruby Enterprise Edition). When I navigate to the main page, I get the following in my production.log (along with a 500 Internal Server Error from Apache): ActionView::TemplateError (uninitialized constant Haml::Filters::Markdown) in app/views/sessions/new.haml I have the haml and RedCloth gems installed: \*\*\* LOCAL GEMS \*\*\* […] haml (3.0.18) RedCloth (4.2.3) That constant is defined when I refer to it in a Rails console: # script/console production Loading production environment. > > Haml::Filters::Markdown > > =\> Haml::Filters::Markdown The problem doesn’t occur in development, and the gems installed and codebase are the same as far as I can tell. Any idea what is causing this? ---
**Author:** ![JRJRJR](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/dc4da7/32.png) [@JRJRJR](https://www.ruby-forum.com/u/JRJRJR)\ **Post date:** [September 8, 2010, 9:03am UTC](https://www.ruby-forum.com/t/deploying-a-rails-app-uninitialized-constant-haml-markdown/194633/2 "2010-09-08T09:03:39Z")
On Sep 7, 10:22 pm, JR [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Internal Server Error from Apache): > > That constant is defined when I refer to it in a Rails console: > > # script/console production > > Loading production environment.\>\> Haml::Filters::Markdown > > =\> Haml::Filters::Markdown > > The problem doesn’t occur in development, and the gems installed and > codebase are the same as far as I can tell. Any idea what is causing > this? How are you loading the haml gem? If you are loading it at the bottom of environment.rb (outside the Rails::Initializer.run block ) then the gem is loaded after rails preloads your application code. This preload only happens in production mode, which is why it doesn’t matter in development Fred ---
**Author:** ![JRJRJR](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/dc4da7/32.png) [@JRJRJR](https://www.ruby-forum.com/u/JRJRJR)\ **Post date:** [September 8, 2010, 6:14pm UTC](https://www.ruby-forum.com/t/deploying-a-rails-app-uninitialized-constant-haml-markdown/194633/3 "2010-09-08T18:14:01Z")
Thanks for the info. I poked around, and see that haml is installed as a plugin, not a gem (all the files are in vendor/plugins/haml). It sounds like all you should have to do then is name files \*.haml and it should work ([ruby - How do I get Haml to work with Rails? - Stack Overflow](http://stackoverflow.com/questions/99211/how-do-i-get-) haml-to-work-with-rails). I should also mention that it not only works in development, but in production mode on another server. I’m actually moving an existing application from one server to another by setting up the environment, moving the codebase over, and deploying it. As far as I know everything is the same on the new server (gems installed, code, etc.), so I don’t know why it’s not working and am at a loss as to where to start troubleshooting. Any help is appreciated. Thanks! On Sep 7, 11:57 pm, Frederick C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![JRJRJR](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/dc4da7/32.png) [@JRJRJR](https://www.ruby-forum.com/u/JRJRJR)\ **Post date:** [September 8, 2010, 10:52pm UTC](https://www.ruby-forum.com/t/deploying-a-rails-app-uninitialized-constant-haml-markdown/194633/4 "2010-09-08T22:52:08Z")
After some more investigation, I realized the application/page load just fine when I start them with “script/server production”. So the issue has something to do with the way Passenger is setting up the environment, I guess. ---
**Author:** ![JRJRJR](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/dc4da7/32.png) [@JRJRJR](https://www.ruby-forum.com/u/JRJRJR)\ **Post date:** [September 17, 2010, 12:16am UTC](https://www.ruby-forum.com/t/deploying-a-rails-app-uninitialized-constant-haml-markdown/194633/5 "2010-09-17T00:16:20Z")
Just in case someone comes searching for this, I narrowed down the problem to the BlueCloth gem. Removing the gem removes this problem, installing it again causes it again. That’s as far as I was able to get…