Austin Seipp
As far as I'm aware, Dynamic-by-default GHC is actually broken, and I don't know for how long this has been the case.
For some history: originally when all this was being decided to try and fix the linker issues in GHC, dynamic by default was considered an option, but was rejected in favor of DynamicGhcPrograms. Why was it rejected? Well, dynamic by default particularly hurts 32bit x86, which suffers from a very pathetic set of registers, and dynamic programs steal one of these for the GOT (%ebx IIRC).
On the other hand, DynamicGhcPrograms instead means GHC builds everything statically, *except itself*, which it builds as a dynamically linked executable. The idea is you dynamically link GHC itself to fix linker issues, and end-user programs remain static, which is the expected mode of operation.
Thank you for the detailed explanation (although I still don't understand why DYNAMIC_BY_DEFAULT by default wasn't kept for x64.) Where does GhcDynamic fit into this?