I work with a multi-mloc application in fpc. We have migrated the code over many compiler versions with hardly any issues at all. With every update they post a

I work with a multi-mloc application in fpc. We have migrated the code over many compiler versions with hardly any issues at all. With every update they post a list of things breaks compatibility, and if you are affected, the refactoring tools are almost always enough. We had two tries at a full recompile migrating from 2.6.something to 3.0.2, and passed all tests within 13 hours of starting the process. (some of the larger stuff were however already fixed since we keep a close eye on the development).