Ruby - LoadError enc/trans/single_byte

Question

I encountered a weird problem while using ActiveRecord::Store module in my Ruby on Rails app. As I understand, this module use 'serialize' method under the hood so it just serialize your data to yaml format with ruby built-in psych gem.

It works OK most of the time, but sometimes I get 500 error with the following message:

LoadError (cannot load such file -- enc/trans/single_byte):
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/emitter.rb:27:in `write'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/emitter.rb:27:in `end_document'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/emitter.rb:27:in `visit_Psych_Nodes_Document'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/emitter.rb:20:in `block in visit_Psych_Nodes_Stream'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/emitter.rb:20:in `each'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/emitter.rb:20:in `visit_Psych_Nodes_Stream'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych/nodes/node.rb:46:in `yaml'
~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/psych.rb:243:in `dump'

As you can see, I use rbenv and ruby 1.9.3-p286. My system is Ubuntu 11.10. Required file exists ~/.rbenv/versions/1.9.3-p286/lib/ruby/1.9.1/i686-linux/enc/trans/single_byte.so. The same error I encountered with ruby 1.9.3-p194. And the most weird part of this problem that this error occurs from time to time.

So maybe someone encountered this problem too and has already found a solution? Or does it seem more like a bug in psych and I should file it to its maintainer?

Thanks in advance for any help!

EDIT: the problem isn't directrly related to psych gem. It's general problem with unusual ruby setup. See the accepted answer below for details.

Answer 1

Is this happening within the cozy confines of your development environment? If so, I'd consider running it under pry-rescue's Pry.rescue do … end block and poking around while there.

I suspect a data difference. Is there any non-ASCII intentionally involved in this tree? You could hunt it down with something like this:

ruby -e 'Dir["**/*.yml"].each{|e| File.read(e)[/[^\x0-\x7f]/] and puts e}' 

As you indicated below, the rbenv installation is shared with other users, so be sure to redo the permissions upon any change:

 chmod a+r -R ~/.rbenv/

Or perhaps create a shared group, such as src, then:

 chgrp src ~/.rbenv && chmod g+r -R ~/.rbenv