protobuf-py3 Homebrew formula

protobuf-py3.rb

# Place in /usr/local/Library/Formula/, then
# brew install protobuf-py3

class ProtobufPy3 < Formula
  url "https://github.com/GreatFruitOmsk/protobuf-py3/archive/2.5.1.tar.gz"
  version "2.5.1"
  sha256 "496484244288b6e9b7d94baac71a3c0ea19c2a381a8a8685f0ff4235e81b1b38"

  conflicts_with "protobuf", :because => "protobuf-py3 is incompatible with protobuf"

  option :universal
  option :cxx11

  # this will double the build time approximately if enabled
  option "with-check", "Run build-time check"

  depends_on :python => :optional
  depends_on :autoconf => :build
  depends_on :automake => :build
  depends_on :libtool => :build

  fails_with :llvm do
    build 2334
  end

  def install
    # Don't build in debug mode. See:
    # https://github.com/Homebrew/homebrew/issues/9279
    ENV.prepend "CXXFLAGS", "-DNDEBUG"
    ENV.universal_binary if build.universal?
    ENV.cxx11 if build.cxx11?

    system "./autogen.sh"
    system "./configure", "--disable-debug",
                          "--disable-dependency-tracking",
                          "--prefix=#{prefix}",
                          "--with-zlib"
    system "make"
    system "make", "check" if build.with? "check" || build.bottle?
    system "make", "install"

    # Install editor support and examples
    doc.install "editors", "examples"

    if build.with? "python"
      chdir "python" do
        ENV["PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION"] = "cpp"
        ENV.append_to_cflags "-I#{include}"
        ENV.append_to_cflags "-L#{lib}"
        args = Language::Python.setup_install_args libexec
        system "python", *args
      end
      site_packages = "lib/python2.7/site-packages"
      pth_contents = "import site; site.addsitedir('#{libexec/site_packages}')\n"
      (prefix/site_packages/"homebrew-protobuf.pth").write pth_contents
    end
  end

  def caveats; <<-EOS.undent
    Editor support and examples have been installed to:
      #{doc}
    EOS
  end

  test do
    (testpath/"test.proto").write <<-EOS.undent
      package test;
      message TestCase {
        required string name = 4;
      }
      message Test {
        repeated TestCase case = 1;
      }
    EOS
    system bin/"protoc", "test.proto", "--cpp_out=."
    system "python", "-c", "import google.protobuf" if build.with? "python"
  end
end