Debug a Jekyll GitHub page which hasn’t been run locally before

I was adding a posts-by-tags page to my Jekyll blog. Previously I have gotten away with never running the Jekyll site locally thanks to GitHub actions however while adding a new feature I came across a generic error I needed to debug locally.

Undefined method gsub for integer

Below is the error message:

Liquid Exception: undefined method `gsub' for 2003:Integer

Upon searching this someone else had a similar issue but this didn’t help me to narrow this down enough to fix it: Liquid Exception: undefined method `gsub’ for 2012:Integer in /_layouts/post.html

Looking at the official Jekyll docs we get some pointers on how to setup the local development environment: https://jekyllrb.com/docs/

• I run the following commands which clone my blog to the local machine.
• The Jekyll new will need to have blog replaced with whatever your repos name is.
• The --force flag will overwrite anything that conflicts with a Jekyll template config.
• Gemfile and .gitignore is really all it adds, you should still run with --force so the URLs are localhost not github.io
• I just scrap the changes in git from jekyll new besides the ones I manually made to patch the bugs once I am done debugging.

git clone https://github.com/2E0PGS/blog.git

jekyll new blog --force

cd blog

bundle exec jekyll serve

My particular bug turned out to be I had a tag which was just a lone int: - 2003

I fixed and finished implementing my posts-by-tags page in commits:

• 4ebab2dbcbd9bd49e4b43db686934c5a454824df
• deceef47d6bd7578aa3f94d644847e28196ba056
• 49019a3b688f74a32130e4d2b0273090580cf6f3

RSS feed

After fixing the first bug I then came across a second bug thanks to a large code block I had in another post with lots of special chars.

Jekyll Feed: Generating feed for posts

I fixed this in commit: af7a60060b2bab05d0805d1443e1674a4d8e26b9 with my custom variable: feed_exclude_content: true

TODO

Checkout the following variables more:

• thumbnail:
• series:
• site.related_posts

Add the actual RSS feed error instead of the line before the error.