What does "<top (required)>" mean in a Ruby stack trace? - ruby

Question

In Ruby 1.9.2 stack trace I frequently see the method given as <top (required)>, as in this section of stack below. What does this mean? Is my Ruby install subtly broken?
Could not find abstract-1.0.0 in any of the sources
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/spec_set.rb:87:in `block in materialize'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/spec_set.rb:81:in `map!'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/spec_set.rb:81:in `materialize'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/definition.rb:90:in `specs'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/definition.rb:135:in `specs_for'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/definition.rb:124:in `requested_specs'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/environment.rb:23:in `requested_specs'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/runtime.rb:11:in `setup'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler.rb:107:in `setup'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.13/lib/bundler/setup.rb:14:in `<top (required)>'
<internal:lib/rubygems/custom_require>:33:in `require'
<internal:lib/rubygems/custom_require>:33:in `rescue in require'
<internal:lib/rubygems/custom_require>:29:in `require'

Answer 1

It's the top level of a file i.e. whatever gets run when the file is required.
So if something fails during the setup of a library (for example some required file isn't found) it will show up in the stacktrace like that.

Answer 2

If everything you required is correct, it could mean that you're trying to create a class with a name that already exists for a module. For example the following file :
class Test
end
Will raise :
<top (required)>': Test is not a class (TypeError)
Because Test is implicitely a module.

Answer 3

I ran into this error of <top (required)> when I was doing the tutorial in the book "Jump Start Sinatra."
I got rid of the error by making sure that I ran sudo gem install <GEM_IN_YOUR_FILE>. So in my case I had a main.rb and in that file I had this
require 'sinatra'
require 'sinatra-contrib'
So I went back into the root of my project and ran sudo gem install sinatra and sudo gem install sinatra-contrib and then my project worked fine.
Your errors will vary, but because this is what I found when I searched on Google, I know others will come here for similar reasons. And I offer this solution to at least get you thinking in the right direction since this worked for me.

Answer 4

I had the same problem. Solved it by converting .rb files encoding to UTF-8-BOM using Notepad++.

Answer 5

Ninto's answer makes total sense. It's a stack trace that you get one things fail. I was running my tests by doing:
bundle exec rspec spec
and what I got was:
An error occurred while loading ./spec/foodie_spec.rb.
Failure/Error: require 'foodie/food'
SyntaxError:
/Users/honey/Dev/foodie/funnex/lib/funnex/food.rb:17: syntax error, unexpected end-of-input, expecting end
# ./lib/foodie.rb:4:in `require'
# ./lib/foodie.rb:4:in `<top (required)>'
# ./spec/foodie_spec.rb:1:in `require'
# ./spec/foodie_spec.rb:1:in `<top (required)>'
No examples found.
Finished in 0.00002 seconds (files took 0.07998 seconds to load)
0 examples, 0 failures, 1 error occurred outside of examples
All I was doing wrong in my case was that I was missing and end.
But to understand the stack trace more, start from bottom of the commented out lines ie this line:
# ./spec/foodie_spec.rb:1:in `<top (required)>'
At line 1 of foodie_spec I had require 'foodie'
At line 4 of foodie.rb I had require 'foodie/food'
I errored out at line 17 of foodie/food
Stack traces in Ruby are also named backtraces or stack traceback