Writes the file containing the arguments for building this gem’s
extensions.
# File lib/rubygems/installer.rb, line 881
def write_build_info_file
return if @build_args.empty?
build_info_dir = File.join gem_home, 'build_info'
FileUtils.mkdir_p build_info_dir
build_info_file = File.join build_info_dir, "#{spec.full_name}.info"
File.open build_info_file, 'w' do |io|
@build_args.each do |arg|
io.puts arg
end
end
end