Workaround issue with Jeweler and rake-compiler

gistfile1.rb

# Hack to avoid "allocator undefined for Proc" issue when unpacking Gems:
# gemspec provided by Jeweler uses Rake::FileList for files, test_files and
# extra_rdoc_files, and procs cannot be marshalled.

# Jeweler Issue GH-73
# Workaround by Alex Coles (myabc)
def gemspec
  @clean_gemspec ||= eval("#{Rake.application.jeweler.gemspec.to_ruby}") # $SAFE = 3\n
end

# Define your extension normally, using the +gemspec+ defined above
Rake::ExtensionTask.new('my_extension', gemspec) do |ext|
  # ...
end