no marshal_dump is defined for class Mutex #1
Description
/usr/local/lib/ruby/site_ruby/1.9.1/transaction/simple.rb:176:in dump': no marshal_dump is defined for class Mutex (TypeError) from /usr/local/lib/ruby/site_ruby/1.9.1/transaction/simple.rb:176:instart_transaction'
from /usr/local/lib/ruby/site_ruby/1.9.1/transaction/simple/group.rb:102:in block in start_transaction' from /usr/local/lib/ruby/site_ruby/1.9.1/transaction/simple/group.rb:102:ineach'
from /usr/local/lib/ruby/site_ruby/1.9.1/transaction/simple/group.rb:102:in start_transaction' from /usr/local/lib/ruby/site_ruby/1.9.1/pdf/simpletable.rb:396:inrender_on'