Set -dynamic-system-linker if musl and not x86_64

Author: angerman

compiler/ghc/default.nix

@@ -322,7 +322,10 @@ let
       # `-fexternal-dynamic-refs` causes `undefined reference` errors when building GHC cross compiler for windows
       + lib.optionalString (enableRelocatedStaticLibs && targetPlatform.isx86_64 && !targetPlatform.isWindows)
         " '*.*.ghc.*.opts += -fexternal-dynamic-refs'"
-      + lib.optionalString targetPlatform.isAndroid
+      # The fact that we need to set this here is pretty idiotic. GHC should figure this out on it's own.
+      # Either have a runtime flag/setting to disable it or if dlopen fails, remember that it failed and
+      # fall back to non-dynamic. We only have x86_64 dynamic linker with musl.
+      + lib.optionalString targetPlatform.isAndroid || (targetPlatform.isMusl && !targetPlatform.isx86)
         " '*.ghc.cabal.configure.opts += --flags=-dynamic-system-linker'"
       # The following is required if we build on aarch64-darwin for aarch64-iOS. Otherwise older
       # iPhones/iPads/... won't understand the compiled code, as the compiler will emit LDSETALH