The curious case of the disappearing hash - ruby-on-rails

Question

Here is a hash:
#rolesHash = {:update => {:link => 1, :task => 36}, :delete => {:link => 2, :job => 14}}
I'm getting the following strange characteristics when trying to access it:
#rolesHash[:update].present? # true
#rolesHash[:update].class # Hash
#rolesHash[:update].keys # undefined method nil for nil:NilClass
#rolesHash[:update][:task] # expecting '36' but get undefined method nil for nil:NilClass
Why can't I access this hash properly?
Detail:
Controller:
14: #recruiters = #company.recruiters
15: render layout: 'notice'
View:
<% #recruiters.each do |recruiter| %>
<% #user = User.find_by_roleable_type_and_roleable_id("Recruiter", recruiter.id) %>
<% #rolesHash = {} %>
<% roles = #user.roles.where("user_id = ? AND company_id = ?", #user.id, #company.id) %>
<% roles.each{|r| #rolesHash[r.role.to_sym] ||= {}; #rolesHash[r.role.to_sym][r.roleable_type.to_sym] = r.roleable_id}
...
<%= #rolesHash[:delete][:job] # error
...
<% end %>
Trace
undefined method `[]' for nil:NilClass
Extracted source (around line #148):
147:
148: <%= #rolesHash[:delete][:job] %>
149:
Rails.root: /Users/ss/Documents/ss/app
app/views/recruiters/index.html.erb:148:in `block in _app_views_recruiters_index_html_erb__298609598644026366_70131760233080'
activerecord (3.2.13) lib/active_record/relation/delegation.rb:6:in `each'
activerecord (3.2.13) lib/active_record/relation/delegation.rb:6:in `each'
app/views/recruiters/index.html.erb:134:in `_app_views_recruiters_index_html_erb__298609598644026366_70131760233080'
actionpack (3.2.13) lib/action_view/template.rb:145:in `block in render'
activesupport (3.2.13) lib/active_support/notifications.rb:125:in `instrument'
actionpack (3.2.13) lib/action_view/template.rb:143:in `render'
actionpack (3.2.13) lib/action_view/renderer/template_renderer.rb:47:in `block (2 levels) in render_template'
actionpack (3.2.13) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
activesupport (3.2.13) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.13) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.13) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.13) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
actionpack (3.2.13) lib/action_view/renderer/template_renderer.rb:46:in `block in render_template'
actionpack (3.2.13) lib/action_view/renderer/template_renderer.rb:54:in `render_with_layout'
actionpack (3.2.13) lib/action_view/renderer/template_renderer.rb:45:in `render_template'
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actionpack (3.2.13) lib/action_view/renderer/renderer.rb:36:in `render_template'
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activesupport (3.2.13) lib/active_support/core_ext/benchmark.rb:5:in `block in ms'
/Users/ss/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/benchmark.rb:296:in `realtime'
activesupport (3.2.13) lib/active_support/core_ext/benchmark.rb:5:in `ms'
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activerecord (3.2.13) lib/active_record/railties/controller_runtime.rb:24:in `cleanup_view_runtime'
actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:39:in `render'
app/controllers/recruiters_controller.rb:15:in `index'
actionpack (3.2.13) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.2.13) lib/abstract_controller/base.rb:167:in `process_action'
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actionpack (3.2.13) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
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/Users/ss/.rvm/gems/ruby-2.0.0-p481/bundler/gems/rails-dev-boost-bf49caca6670/lib/rails_development_boost/async.rb:12:in `block in call'
/Users/ss/.rvm/gems/ruby-2.0.0-p481/bundler/gems/rails-dev-boost-bf49caca6670/lib/rails_development_boost/async.rb:39:in `block in synchronize'
/Users/ss/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/Users/ss/.rvm/gems/ruby-2.0.0-p481/bundler/gems/rails-dev-boost-bf49caca6670/lib/rails_development_boost/async.rb:39:in `synchronize'
/Users/ss/.rvm/gems/ruby-2.0.0-p481/bundler/gems/rails-dev-boost-bf49caca6670/lib/rails_development_boost/async.rb:12:in `call'
newrelic_rpm (3.9.4.245) lib/new_relic/agent/instrumentation/middleware_tracing.rb:57:in `call'
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newrelic_rpm (3.9.4.245) lib/new_relic/rack/agent_hooks.rb:26:in `traced_call'
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script/rails:7:in `require'
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Answer 1

I guess that your call to #user.roles.where("user_id = ? AND company_id = ?", #user.id, #company.id) returns no rows. This would cause roles to be empty, which in turn means roles.each doesn't iterate over anything and the block is never called.
Thus, when you reach
<%= #rolesHash[:delete][:job]
#rolesHash is still {}, and the line is going to fail with the error you've pasted.
To verify this I would start by adding two debug lines in your output. One right before iterating:
<% Rails.logger.debug roles.inspect %>
<% roles.each{|r| #rolesHash[r.role.to_sym] ||= {}; #rolesHash[r.role.to_sym][r.roleable_type.to_sym] = r.roleable_id}
and one right before accessing #rolesHash:
<% Rails.logger.debug #rolesHash.inspect %>
<%= #rolesHash[:delete][:job] %>
Then, looking in your logfile should allow you to see if the actual data matches the data you expect to be present.