Suddenly I lost the styling on my application served on Heroku. The reason for that was that all the assets (CSS, JavaScript, images) could not be found. The mysterious error:

ActionController::RoutingError (No route matches "/stylesheets/basic.css" with {:method=>:get}):

was indicating that there is some routing problem. Actually it wasn't that exactly. I have added to my application config.ru file which I needed for serving it from Pow in my local development environment. The Momoro Hoax provided a solution which was to change slightly the content of the config.ru. Of course removing config.ru from that app and not keeping it in git repository would also solve that problem. 

After many months of postponing the upgrade from Snow Leopard to Lion, observing others using Lion, for office work and for web development work, finally I have decided to at least try the upgrade.

I've got myself a bigger HDD as the one in the laptop was already full. Friday night all the work for the week was finished, so if I could make it over the weekend and it worked, I could start on Monday working on Lion. The critical bit is to have the Ruby on Rails environment working. 

1. I have cloned my disk with Carbon Copy Cloner into the new one. I left it over night, it took 5 hours for 300GB of data over USB.
   
2. On Saturday morning I started installing Lion on the cloned drive. During the day I've run the Software Updates. At the evening I've logged into my account where I have the development set up. I checked if Pow was still running one of my applications locally. It didn't, but Webrick was enough and all rvm with different gem sets seemed to be fine. It was taking a while to convert emails (21GB) into the new Mail version. I left it overnight.
3. Today morning I have looked into how the new Mail works. Finally I can read the email conversations normally. The Mail is splitting quoted parts of emails into separated emails within conversation and allows sorting it from oldest to newest and the other way round. I can now see the response under the quoted email even if the whole world is doing it in corporation style with responding above. Well done Apple!
4. Suddenly Pow is working, no problem. I did not have to reinstall anything from my development workshop. I have decided to call it a day. I'm switching my work environment to Lion. 

Now onto swapping the drive inside the MacBook Pro...