Undefined Method 'titlecase!' When Building from Travis

[tohuw]

Any idea why this happens? I tried including titlecase in my Gemfile, but it didn't help.

Here's the commit and build.

Here's the trace:

/home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/octopress-linkblog-2.0.2/lib/octopress-linkblog.rb:43:in `add_post_vars': undefined method `titlecase!' for nil:NilClass (NoMethodError)
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/octopress-linkblog-2.0.2/lib/octopress-linkblog.rb:36:in `post_init'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/octopress-hooks-2.6.1/lib/octopress-hooks.rb:374:in `block in post_init'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/octopress-hooks-2.6.1/lib/octopress-hooks.rb:373:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/octopress-hooks-2.6.1/lib/octopress-hooks.rb:373:in `post_init'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/octopress-hooks-2.6.1/lib/octopress-hooks.rb:325:in `initialize'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:220:in `new'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:220:in `block in read_content'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:219:in `map'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:219:in `read_content'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:195:in `read_posts'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:167:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:176:in `block in read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:172:in `read_directories'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:151:in `read'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/octopress-hooks-2.6.1/lib/octopress-hooks.rb:181:in `read'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/site.rb:49:in `process'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/command.rb:28:in `process_site'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/commands/build.rb:56:in `build'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/commands/build.rb:34:in `process'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/lib/jekyll/commands/build.rb:18:in `block (2 levels) in init_with_program'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/mercenary-0.3.5/lib/mercenary/command.rb:220:in `call'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/mercenary-0.3.5/lib/mercenary/command.rb:220:in `block in execute'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/mercenary-0.3.5/lib/mercenary/command.rb:220:in `each'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/mercenary-0.3.5/lib/mercenary/command.rb:220:in `execute'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/mercenary-0.3.5/lib/mercenary/program.rb:42:in `go'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/mercenary-0.3.5/lib/mercenary.rb:19:in `program'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/gems/jekyll-2.5.3/bin/jekyll:20:in `<top (required)>'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/bin/jekyll:23:in `load'
    from /home/travis/build/tohuw/tohuw.net/vendor/bundle/ruby/2.2.0/bin/jekyll:23:in `<main>'