anchor.diff:      buildPhase = builder crossB2Args;
       installPhase = installer crossB2Args;
       postFixup = fixup;
  -  } // optionalAttrs (stdenv.cross.libc == "msvcrt") {
  +  } // optionalAttrs (hostPlatform.libc == "msvcrt") {
       patches = fetchurl {
         url = "https://svn.boost.org/trac/boost/raw-attachment/ticket/7262/"
             + "boost-mingw.patch";
  
positive.code:     "--user-config=user-config.jam"
      "toolset=gcc-cross"
      "--without-python"
    ] ++ optionals (stdenv.cross.libc == "msvcrt") [
      "target-os=windows"
      "threadapi=win32"
      "binary-format=pe"
      "address-model=${if hasPrefix "x86_64-" stdenv.cross.config then "64" else "32"}"
      "architecture=x86"
    ];
    crossB2Args = concatStringsSep " " (genericB2Flags ++ crossB2Flags);
  
negative.code:       find include \( -name '*.hpp' -or -name '*.h' -or -name '*.ipp' \) \
          -exec sed '1i#line 1 "{}"' -i '{}' \;
      )
    '' + optionalString (hostPlatform.libc == "msvcrt") ''
      ${stdenv.cc.prefix}ranlib "$out/lib/"*.a
    '';
  
  in
  