Using jekyll with --watch flag causing build errors

Question

I am using Jekyll on Windows 8 to work on a small project for work. So far I am loving Jekyll, but have encountered an issue when trying to serve my site with the --watch flag, which allows the site to update on refresh when changes are made to the code.

When I run my Jekyll sites I will open my cmd and cd to the proper directory. Per the Jekyll docs, I will execute chcp 65001 in the directory to change the encoding to UTF-8. Now, when I run jekyll serve -w or jekyll serve --watch I get an error dump consisting of the following:

C:\Dropbox\Workbench\lunch-and-learn>jekyll serve -w
    Configuration file: C:/Dropbox/Workbench/lunch-and-learn/_config.yml
                Source: C:/Dropbox/Workbench/lunch-and-learn
           Destination: C:/Dropbox/Workbench/lunch-and-learn/_site
          Generating... done.
     Auto-regeneration: enabled
C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:55:in `require': cannot load such file -- wdm (LoadError)
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:55:in `require'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapter.rb:207:in `load_dependent_adapter'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapters/windows.rb:33:in `load_dependent_adapter'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapter.rb:198:in `usable?'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapters/windows.rb:25:in `usable?'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapter.rb:190:in `usable_and_works?'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapter.rb:57:in `block in select_and_initialize'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapter.rb:55:in `each'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/adapter.rb:55:in `select_and_initialize'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/listener.rb:291:in `initialize_adapter'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/listener.rb:283:in `setup'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/listen-1.3.1/lib/listen/listener.rb:52:in `start'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/jekyll-1.4.1/lib/jekyll/commands/build.rb:56:in `watch'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/jekyll-1.4.1/lib/jekyll/commands/build.rb:8:in `process'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/jekyll-1.4.1/bin/jekyll:97:in `block (2 levels) in <top (required)>'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/commander-4.1.5/lib/commander/command.rb:180:in `call'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/commander-4.1.5/lib/commander/command.rb:180:in `call'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/commander-4.1.5/lib/commander/command.rb:155:in `run'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/commander-4.1.5/lib/commander/runner.rb:402:in `run_active_command'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/commander-4.1.5/lib/commander/runner.rb:66:in `run!'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/commander-4.1.5/lib/commander/delegates.rb:11:in `run!'
    from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/commander-4.1.5/lib/commander/import.rb:10:in `block in <top (required)>'

It is worth noting that when I run the site with simply jekyll serve, without the --watch or -w flags, the site builds and serves just fine to port 4000. However this is not ideal for development.

Link to Jekyll Usage

Answer 1

As shown in the error message, wdm is not found.

First, update your gems

gem update

Then, manually install wdm

gem install wdm