Fix aarch64 musl TH code that uses C++ (#2412)

* Fix aarch64 musl TH code that uses C++

* There is still an issue with cross compiling (not C++ related)

* There is still an issue with cross compiling (not C++ related)

Author: hamishmack

builder/comp-builder.nix

@@ -338,7 +338,7 @@ let
     }
     // lib.optionalAttrs stdenv.hostPlatform.isMusl {
       # This fixes musl compilation of TH code that depends on C++ (for instance TH code that uses the double-conversion package)
-      LD_LIBRARY_PATH="${pkgs.buildPackages.gcc-unwrapped.lib}/x86_64-unknown-linux-musl/lib";
+      LD_LIBRARY_PATH="${pkgs.buildPackages.gcc-unwrapped.lib}/${stdenv.hostPlatform.config}/lib";
     }
     // lib.optionalAttrs dontUpdateAutotoolsGnuConfigScripts {
       inherit dontUpdateAutotoolsGnuConfigScripts;

test/cabal.project.local

@@ -29,7 +29,7 @@ repository head.hackage.ghc.haskell.org
      f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
      26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
      7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
-  --sha256: sha256-3icOgmtUh9WxDFfmmSHgTKhlfWJ6Yb5jYGYBcnK7d0A=
+  --sha256: sha256-ywti4TWiuFGJtnHaMMPhk3Ms2hXfsXMC1LMcWnI9K6I=
 
 repository ghcjs-overlay
   url: https://raw.githubusercontent.com/input-output-hk/hackage-overlay-ghcjs/ffb32dce467b9a4d27be759fdd2740a6edd09d0b

test/th-dlls/default.nix

@@ -20,8 +20,12 @@ let
 
 in recurseIntoAttrs {
   meta.disabled = stdenv.hostPlatform.isGhcjs
-    # On aarch64 this test also breaks form musl builds (including cross compiles on x86_64-linux)
-    || (stdenv.hostPlatform.isAarch64 && stdenv.hostPlatform.isMusl)
+    # On aarch64 this test breaks form musl cross compiles on x86_64-linux
+    # Error is:
+    # iserv-proxy-interpreter: internal error: 0x0 address for .LANCHOR1 + 0 of type 562
+    #   in tmp/nix/store/kgprix3jn2w320flxpf7yr29f7dczykr-libsodium-aarch64-unknown-linux-musl-1.0.18/lib/libsodium.a
+    #   (#103:librdrand_la-randombytes_internal_random.o) for relocation 4 in section 1 of kind: 0
+    || (stdenv.hostPlatform.isAarch64 && stdenv.hostPlatform.isMusl && !stdenv.buildPlatform.isAarch64)
     # Not sure why this is failing with a seg fault
     || (builtins.elem compiler-nix-name ["ghc9102" "ghc9102llvm"] && stdenv.hostPlatform.isAndroid && stdenv.hostPlatform.isAarch32)
     # unhandled ELF relocation(Rel) type 10