anchor.diff:  { name ? "", stdenv, lib, nativeTools, nativeLibc, nativePrefix ? ""
   , gcc ? null, libc ? null, binutils ? null, coreutils ? null, shell ? ""
   , zlib ? null
  +, hostPlatform, targetPlatform
   }:
   
   assert nativeTools -> nativePrefix != "";
  
positive.code:     # the style in the gcc-cross-wrapper, but to keep a stable stdenv now I
      # do this sufficient if/else.
      dynamicLinker =
        (if stdenv.cross.arch == "arm" then "ld-linux.so.3" else
         if stdenv.cross.arch == "mips" then "ld.so.1" else
         if stdenv.lib.hasSuffix "pc-gnu" stdenv.cross.config then "ld.so.1" else
         abort "don't know the name of the dynamic linker for this platform");
    };
  
  
negative.code:         + " (wrapper script)";
      };
  
    # The dynamic linker has different names on different platforms.
    dynamicLinker =
      if !nativeLibc then
        (if targetPlatform.system == "i686-linux"     then "ld-linux.so.2" else
         if targetPlatform.system == "x86_64-linux"   then "ld-linux-x86-64.so.2" else
         # ARM with a wildcard, which can be "" or "-armhf".
         if targetPlatform.isArm32                    then "ld-linux*.so.3" else
         if targetPlatform.system == "aarch64-linux"  then "ld-linux-aarch64.so.1" else
         if targetPlatform.system == "powerpc-linux"  then "ld.so.1" else
         if targetPlatform.system == "mips64el-linux" then "ld.so.1" else
         if targetPlatform.system == "x86_64-darwin"  then "/usr/lib/dyld" else
         if stdenv.lib.hasSuffix "pc-gnu" targetPlatform.config then "ld.so.1" else
         builtins.trace
           "Don't know the name of the dynamic linker for platform ${targetPlatform.config}, so guessing instead."
           null)
      else "";
  }
  