racket: support aarch64-darwin

According to https://reviews.llvm.org/D96164, aarch64-darwin executables
require at least an ad hoc signature.

The build tool from the racket repo tries to sign $out/bin/racket but
errors out, because that binary already has a signature.

It is not clear yet at which stage the signature was introduced. This
patch removes the existing signature always before calling
add-ad-hoc-signature to circumvent that error.

pkgs/development/interpreters/racket/default.nix

@@ -78,6 +78,13 @@ stdenv.mkDerivation rec {
     # fail to detect its variant at runtime.
     # See: https://github.com/NixOS/nixpkgs/issues/114993#issuecomment-812951247
     ./force-cs-variant.patch
+
+    # The entry point binary $out/bin/racket is codesigned at least once. The
+    # following error is triggered as a result.
+    # (error 'add-ad-hoc-signature "file already has a signature")
+    # We always remove the existing signature then call add-ad-hoc-signature to
+    # circumvent this error.
+    ./force-remove-codesign-then-add.patch
   ];
 
   preConfigure = ''
@@ -90,10 +97,34 @@ stdenv.mkDerivation rec {
         --replace /bin/rm ${coreutils}/bin/rm \
         --replace /bin/true ${coreutils}/bin/true
     done
+
+    # The configure script forces using `libtool -o` as AR on Darwin. But, the
+    # `-o` option is only available from Apple libtool. GNU ar works here.
+    substituteInPlace src/ChezScheme/zlib/configure \
+        --replace 'ARFLAGS="-o"' 'AR=ar; ARFLAGS="rc"'
+
     mkdir src/build
     cd src/build
 
-    gappsWrapperArgs+=("--prefix" "LD_LIBRARY_PATH" ":" ${LD_LIBRARY_PATH})
+  '' + lib.optionalString stdenv.isLinux ''
+    gappsWrapperArgs+=("--prefix"   "LD_LIBRARY_PATH" ":" ${libPath})
+  '' + lib.optionalString stdenv.isDarwin ''
+    gappsWrapperArgs+=("--prefix" "DYLD_LIBRARY_PATH" ":" ${libPath})
+  ''
+  ;
+
+  preBuild = lib.optionalString stdenv.isDarwin ''
+    # Cannot set DYLD_LIBRARY_PATH as an attr of this drv, becasue dynamic
+    # linker environment variables like this are purged.
+    # See: https://apple.stackexchange.com/a/212954/167199
+
+    # Make builders feed it to dlopen(...). Do not expose all of $libPath to
+    # DYLD_LIBRARY_PATH as the order of looking up symbols like
+    # `__cg_jpeg_resync_to_restart` will be messed up. Our libJPEG.dyllib
+    # expects it from our libTIFF.dylib, but instead it could not be found from
+    # the system `libTIFF.dylib`. DYLD_FALLBACK_LIBRARY_PATH has its own problem
+    # , too.
+    export DYLD_FALLBACK_LIBRARY_PATH="${libPath}"
   '';
 
   shared = if stdenv.isDarwin then "dylib" else "shared";
@@ -119,6 +150,6 @@ stdenv.mkDerivation rec {
     homepage = "https://racket-lang.org/";
     license = with licenses; [ asl20 /* or */ mit ];
     maintainers = with maintainers; [ kkallio henrytill vrthra ];
-    platforms = [ "x86_64-darwin" "x86_64-linux" "aarch64-linux" ];
+    platforms = [ "x86_64-darwin" "x86_64-linux" "aarch64-linux" "aarch64-darwin" ];
   };
 }

pkgs/development/interpreters/racket/force-remove-codesign-then-add.patch

@@ -0,0 +1,11 @@
+--- old/src/mac/codesign.rkt        2022-01-08 18:25:53.000000000 -0500
++++ new/src/mac/codesign.rkt        2022-02-15 15:49:51.000000000 -0500
+@@ -17,6 +17,5 @@
+    #:args (file)
+    file))
+
+-(if remove?
+-    (remove-signature file)
+-    (add-ad-hoc-signature file))
++(remove-signature file)
++(add-ad-hoc-signature file)

pkgs/development/interpreters/racket/minimal.nix

@@ -14,7 +14,7 @@ racket.overrideAttrs (oldAttrs: rec {
       as well as libraries that live in collections. In particular, raco
       and the pkg library are still bundled.
     '';
-    platforms = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" ];
+    platforms = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
     broken = false; # Minimal build does not require working FFI
   };
 })