I've just gotten through a few hours of debugging my Rails app. I seems the gem Ambition, (http://errtheblog.com/post/10722) does not want to work. I was consistently getting 500's, without any kind of error message telling me what was going wrong. I can run irb and load the gem, no problem. But somehow I finally narrowed it down to my config/environment.rb, then the line: "require 'ambition'". I wrapped it in a "begin.. rescue" block, but still got no error message. Removing the line, of course, fixed things.
Why is this gem not working? My guess is that, because it uses ParseTree/RubyInline to do AST hacking, which performs this magick by accessing the raw memory (I think) in one of the Ruby binaries. If Dreamhost has any kind of security, they probably have a watchdog that kills any process trying to do this. I'm going to try and build my own Ruby binary, see if Dreamhost let me get away with that. We'll see..
Anyone else come across this? Any suggestions/confirmations/rebuttals?