I have a symfony-project (2.0.0-DEV = RC5) which i want to upgrade to the latest version (2.0.18). If i just copy my bundles with some changes (for example autoloading path) it still don't work and throwing many errors. Of course i can fix all errors, but there a lot of bundles and it will take too much time. I have think about searching all posts from July 2011 and applying all changes from each release, but i think it too will take much time.
Is there any easier way to solve this problem?
From what I can see in the update file there shouldn't be any significant change between RC5 and 2.0.18.
You should read the CHANGELOG-2.0 file and update your code. It will take a lot of time.
You can do some other things aswell:
The problem is that there isn't something like 'an easy way'. That's why Symfony gets into a Release Process Circle and LTR. You need to choose a way that is good for your application and will not take much time. That's why I don't recommend to upgrade to the latest 2.0.x or 2.1.x version, because that is only supported 8 months. The best is to use the 2.3 in November 2013 and update your application on a regular base (which is easy with composer). But November 2013 is almost a year, which I think is to long.