We see the following after running a summary report:

[root@puppet-dev-01 foreman]# rake reports:summarize RAILS_ENV="production" --trace
(in /usr/local/foreman)

• Invoke reports:summarize (first_time)
• Invoke environment (first_time)
• Execute environment
• Execute reports:summarize
  rake aborted!
  Missing host to link to! Please provide :host parameter or set default_url_options[:host]
  On line #84 of app/views/host_mailer/summary.text.html.erb

81:             <td style="border: 1px solid #FF9933;
    82:               border-collapse: collapse;
    83:               padding: 4px;
    84:               background-color: #FFFFFF;"><%= link_to host.name, host_path(:id => host.id, :host => @url, :only_path => false) %>
    85:             &lt;/td&gt;
    86:             &lt;td style=&quot;border: 1px solid #FF9933;
    87:               border-collapse: collapse;

(eval):16:in `host_path'
    app/views/host_mailer/summary.text.html.erb:84
    app/views/host_mailer/summary.text.html.erb:79:in `each'
    app/views/host_mailer/summary.text.html.erb:79
    lib/tasks/reports.rake:79
    rake (0.8.7) lib/rake.rb:635:in `call'
    rake (0.8.7) lib/rake.rb:635:in `execute'
    rake (0.8.7) lib/rake.rb:630:in `each'
    rake (0.8.7) lib/rake.rb:630:in `execute'
    rake (0.8.7) lib/rake.rb:596:in `invoke_with_call_chain'
    /usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
    rake (0.8.7) lib/rake.rb:589:in `invoke_with_call_chain'
    rake (0.8.7) lib/rake.rb:582:in `invoke'
    rake (0.8.7) lib/rake.rb:2050:in `invoke_task'
    rake (0.8.7) lib/rake.rb:2028:in `top_level'
    rake (0.8.7) lib/rake.rb:2028:in `each'
    rake (0.8.7) lib/rake.rb:2028:in `top_level'
    rake (0.8.7) lib/rake.rb:2067:in `standard_exception_handling'
    rake (0.8.7) lib/rake.rb:2022:in `top_level'
    rake (0.8.7) lib/rake.rb:2000:in `run'
    rake (0.8.7) lib/rake.rb:2067:in `standard_exception_handling'
    rake (0.8.7) lib/rake.rb:1997:in `run'
    rake (0.8.7) bin/rake:31
    /usr/bin/rake:19:in `load'
    /usr/bin/rake:19