You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: gource.rb
    path of file: ./repos/homebrew-core/Formula/g
    
    the code of the file until where you have to start completion: class Gource < Formula
  desc "Version Control Visualization Tool"
  homepage "https://github.com/acau
    
  def install
    # clang on Mt. Lion will try to build against libstdc++,
    # despite -std=gnu++0x
    ENV.libcxx
    ENV.append "LDFLAGS", "-pthread" if OS.linux?

    system "autoreconf", "-f", "-i" if build.head?

    system "./configure", "--disable-dependency-tracking",
                          "--prefix=#{prefix}",
                          "--with-boost=#{Formula["boost"].opt_prefix}",
                          "--without-x"
    system "make", "install"
  end