Troubleshooting frozen object in tzinfo_timezone

ruby-talk
1

Hi. Off and on I get a "can't modify frozen object" when working with the tzinfo_timezone plugin. I've added some debugging in the code to try and track down what goes wrong:

   def tzinfo
     RAILS_DEFAULT_LOGGER.debug("TZINFO STATE '#{@tzinfo}' class #{@tzinfo.class} frozen? #{@tzinfo.frozen?}")
     return @tzinfo if @tzinfo
     RAILS_DEFAULT_LOGGER.debug("TZINFO ASSIGN TO #{MAPPING[name]}")
     begin
       @tzinfo = MAPPING[name]
     rescue TypeError => type_error
       RAILS_DEFAULT_LOGGER.debug("TZINFO TYPE ERROR #{type_error}")
       raise type_error
     end
     RAILS_DEFAULT_LOGGER.debug("TZINFO ASSIGNED TO #{@tzinfo}")
     if String === @tzinfo
       @tzinfo = TZInfo::Timezone.get(@tzinfo)
       MAPPING[name] = @tzinfo
     end
     @tzinfo
   end

When the error occurs, the following makes it to the log:

TZINFO STATE '' class NilClass frozen? false
TZINFO ASSIGN TO Europe/Amsterdam
TZINFO TYPE ERROR can't modify frozen object

Which means, that @tzinfo is nil, and yet, the line

  @tzinfo = MAPPING[name]

Causes a TypeError. MAPPING is a hash. I'm mildly confused. Anyone able to shed some light on what might be the issue or how to dig further into the problem?

ruby 1.8.4 (2005-12-24) [x86_64-linux]

Thanks.

Morten