Looks like my shared host server got rebooted last night, and my Rails app has since broke. I only get the error ..
Rails application failed to start properly
I don't see anything in the Rails logs (i.e. app/logs/production.log). I can run a script/console and interact with the models fine, so the database and code are fine.
I am using Passenger and if I do a 'touch tmp/restart.txt' the file doesn't disappear.
As a test I even generated a completely fresh Rails app and this doesn't even work. I get the default index.html page come up, but when I click 'About you application environment' I get the following error:
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webmaster@xxx and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.