in root.html). Outputs custom og:image with assets_prefix normalisation and non-Google site verification. --> Ruby | zer0-mistakes in _layouts/root.html. What this file adds: - Custom og:image with preview_images.assets_prefix path normalisation for the theme-specific page.preview and page.header.og_image keys. When page.image is set, jekyll-seo-tag handles og:image and this file skips its own og:image output to avoid duplicate tags. - Non-Google site verification tags (Bing, Yandex, Naver, Baidu) Dependencies: - jekyll-seo-tag plugin (loaded in _layouts/root.html via Ruby | zer0-mistakes ) - site.preview_images config in _config.yml =================================================================== --> Ruby | zer0-mistakes Skip to main content
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About
Jekyll v3.10.0
Environment Production
Last Build
2026-04-10 14:49 UTC
Current Environment Production
Build Time Apr 10, 14:49
Jekyll v3.10.0
Build env (JEKYLL_ENV) production
Page Location
Page Info
Layout default
Collection docs
Path _docs/ruby/index.md
URL /docs/ruby/
Date 2026-04-10
Theme Skin
SVG Backgrounds
Layer Opacity
0.6
0.04
0.08

Ruby & Bundler

Jekyll is built with Ruby. Understanding the basics helps with troubleshooting and customization.

Quick Reference

Check Versions

# Ruby version
ruby --version

# Bundler version
bundle --version

# Jekyll version
bundle exec jekyll --version

Common Commands

# Install dependencies from Gemfile
bundle install

# Update all gems
bundle update

# Update specific gem
bundle update jekyll

# Run Jekyll through Bundler
bundle exec jekyll serve

Key Files

File Purpose
Gemfile Lists Ruby gem dependencies
Gemfile.lock Locks exact versions
jekyll-theme-zer0.gemspec Theme gem specification

With Docker

When using Docker, Ruby commands run inside the container:

# Check Ruby version in container
docker-compose exec jekyll ruby --version

# Update gems in container
docker-compose exec jekyll bundle update

Troubleshooting

Gem Installation Errors

# Clear bundle cache
bundle clean --force

# Reinstall everything
rm -rf vendor/bundle
bundle install

Version Conflicts

# Check for outdated gems
bundle outdated

# Update Gemfile.lock
bundle update

Learn More