What's so bad about Template Haskell?

Question

It seems that Template Haskell is often viewed by the Haskell community as an unfortunate convenience. It\'s hard to put into words exactly what I have observed in this rega

Answer 1

One rather pragmatic problem with Template Haskell is that it only works when GHC's bytecode interpreter is available, which is not the case on all architectures. So if your program uses Template Haskell or relies on libraries that use it, it will not run on machines with an ARM, MIPS, S390 or PowerPC CPU.

This is relevant in practice: git-annex is a tool written in Haskell that makes sense to run on machines worrying about storage, such machines often have non-i386-CPUs. Personally, I run git-annex on a NSLU 2 (32 MB of RAM, 266MHz CPU; did you know Haskell works fine on such hardware?) If it would use Template Haskell, this is not possible.

(The situation about GHC on ARM is improving these days a lot and I think 7.4.2 even works, but the point still stands).