Jekyll Cannot Resolve <youtube> Tag

[verticon]

Hello Etienne,

Thank you, and contributors, for creating this Jekyll YouTube plugin. I am attempting to use it for the first time and have encountered a difficulty. Please have a look. I am grateful for any advise.

I have followed your installation guide; I have triple checked. When I generate the site, Jekyll complains:

    ~/verticon.io$ bundle exec rake generate
    ## Generating Site with Jekyll
          write source/stylesheets/screen.css
   Configuration file: /Users/Robert/verticon.io/_config.yml
                       Source: source
                Destination: public
             Generating... 
   Liquid Exception: No such file or directory @ dir_s_mkdir - .jekyll-cache/youtube in about/index.markdown
                                 done.
   Auto-regeneration: disabled. Use --watch to enable.
   ~/verticon.io$ 

The file referenced by the error, about/index.markdown, is where I am attempting to embed the YouTube video. Here are its contents:

    ---
    layout: page
    title: "Welcome To iLand"
    #date: 2020-12-07 11:56
    comments: false
    sharing: true
    footer: false
    ---

    [//]: # This is a comment

    {% img left about/image1.jpg 150 250 One %}
    {% img left about/image2.jpg 150 250 Two %}

    {% video http://localhost:4000/about/MyVideo.mp4 300 200 http://localhost:4000/about/MyPoster %}

    {% youtube 9oDoy0IAKKM %}

If I remove the line with the youtube tag then all is well. "img"and 'video" are tags that are defined by other plugins which reside in the plugins directory along side youtube.rb

[verticon]

I have gone to https://github.com/optikfluffel/octopress-responsive-video-embed (which is, I believe, your starting point), obtained youtube.rb and _rve.scss from there, and put them in place on my site. Voila! Jekyll does not complain
when generating and the YouTube video is properly displayed on the about/index page.

Hmmm. Not sure what to make of this.

Also, @optikfluffel's instructions make no mention of the YouTube API key, or of the yt gem.