ActiveRecord return normal?

Hi Everyone,

I’m totally brand new to RoR. I’m really starting to love coding more now that I’ve found RoR. I have what might be a dumb question, but I’m curious to know this.

Is it normal to get this result:

In the Beginning Rails 4 book

I’m following this step:

irb(main):097:0> article.location = “Toronto, ON”

Here’s what I get:

RuntimeError: can’t modify frozen Hash

** from /Library/Ruby/Gems/2.0.0/gems/activerecord-4.0.1/lib/active_record/attribute_methods/write.rb:45:in `[]=’**

** from /Library/Ruby/Gems/2.0.0/gems/activerecord-4.0.1/lib/active_record/attribute_methods/write.rb:45:in `write_attribute’**

** from /Library/Ruby/Gems/2.0.0/gems/activerecord-4.0.1/lib/active_record/attribute_methods/dirty.rb:70:in `write_attribute’**

** from /Library/Ruby/Gems/2.0.0/gems/activerecord-4.0.1/lib/active_record/attribute_methods/write.rb:21:in `__temp__c6f636164796f6e6=’**

** from (irb):97**

** from /Library/Ruby/Gems/2.0.0/gems/railties-4.0.1/lib/rails/commands/console.rb:90:in `start’**

** from /Library/Ruby/Gems/2.0.0/gems/railties-4.0.1/lib/rails/commands/console.rb:9:in `start’**

** from /Library/Ruby/Gems/2.0.0/gems/railties-4.0.1/lib/rails/commands.rb:62:in `<top (required)>’**

** from bin/rails:4:in `require’**

** from bin/rails:4:in `’**

But in the book they only show:

RuntimeError: can’t modify frozen Hash

Could it be that I’ve set something wrong on my mac when I installed rails or rvm?

I’ve literally followed each part of the book step-by-step.

That sounds like they just didn't want to fill a whole page of the book with stack trace (especially as that part will vary since it depends on where gems are installed)