class Gem::Tasks::Build::Task

def build(path,gemspec)
end

def build_task(name,extname=name)
  directory Project::PKG_DIR
  task :validate
  @project.builds.each do |build,packages|
    gemspec = @project.gemspecs[build]
    path    = packages[extname]
    # define file tasks, so the packages are not needless re-built
    file(path => [Project::PKG_DIR, *gemspec.files]) do
      invoke :validate
      status "Building #{File.basename(path)} ..."
      build(path,gemspec)
    end
    task "build:#{name}:#{build}" => path
    task "build:#{build}"         => "build:#{name}:#{build}"
  end
  gemspec_tasks "build:#{name}"
  desc "Builds all packages" unless task?(:build)
  task :build => "build:#{name}"
end