Install all dependencies specified in Gemfile

This guide covers Phase 4 of the Quick Start — installing Jekyll and the zer0-mistakes theme that powers it-journey.dev. By the end, you'll have a working Jekyll site running locally.

Prerequisites¶

Before starting, confirm these tools are installed:

ruby --version       # 3.2+
bundler --version    # 2.x+
git --version        # 2.x+

If anything is missing, complete the Machine Setup first.

Jekyll also requires:

RubyGems (ships with Ruby)
GCC and Make (included with Xcode CLI on macOS, build-essential on Linux)

If you want to use GitHub Pages, here are the supported dependency versions.

Install Dependencies via Gemfile¶

The IT-Journey repository already includes a Gemfile. If you're starting fresh or want to understand the setup:

cd ~/github/it-journey   # or your project directory

Using the Existing Gemfile¶

# Install all dependencies specified in Gemfile
bundle install

Creating a Gemfile from Scratch¶

If you don't have a Gemfile yet (e.g., starting a new zer0-mistakes site):

cat > Gemfile << 'EOF'
source "https://rubygems.org"

gem 'github-pages'
gem 'jekyll-theme-zer0'
gem 'webrick'
EOF

bundle install

Key gems:

Gem	Purpose
`github-pages`	GitHub Pages-compatible Jekyll build with all supported plugins
`jekyll-theme-zer0`	The zer0-mistakes theme gem for local development
`webrick`	Required web server for Ruby 3.0+

Theme Configuration¶

The zer0-mistakes theme can be loaded in two ways. Which one you use depends on whether you're developing locally or deploying to GitHub Pages.

Option 1: Remote Theme (GitHub Pages Deployment)¶

In your _config.yml:

remote_theme: "bamr87/zer0-mistakes"

This is what GitHub Pages uses when building your site. No gem installation needed on the server.

Option 2: Local Gem (Local/Docker Development)¶

In your _config.yml (or _config_dev.yml):

theme: "jekyll-theme-zer0"

This uses the locally installed gem, which is faster for development and works offline.

Using Both Configs Together¶

The recommended workflow uses the remote theme for production and the local gem for development:

# Development: loads _config_dev.yml overrides (including local theme)
bundle exec jekyll serve --config _config.yml,_config_dev.yml

# Production: uses remote_theme from _config.yml only
JEKYLL_ENV=production bundle exec jekyll build

Verify Your Installation¶

Native Ruby¶

bundle exec jekyll serve
# Open http://localhost:4000 (or 4002 if configured) in your browser

You should see the zer0-mistakes theme with the site title and navigation.

Docker (Alternative)¶

If you prefer Docker (no Ruby installation needed on your host machine):

docker-compose up -d
# Open http://localhost:4002 in your browser

See the Local Development guide for the full Docker workflow.

Common Issues¶

`webrick` LoadError (Ruby 3.0+)¶

If you see cannot load such file -- webrick:

bundle add webrick

Bundler Version Mismatch¶

If bundle install fails with a version error:

gem install bundler
bundle install

Theme Not Loading¶

If pages render without styling:

Confirm remote_theme or theme is set in _config.yml
For local development, ensure jekyll-theme-zer0 is in your Gemfile
Run bundle install again after Gemfile changes
Restart the Jekyll server (Ctrl+C, then bundle exec jekyll serve)

Live Reload¶

Pass --livereload to automatically refresh the browser when files change:

bundle exec jekyll serve --livereload

What's Next¶

Next Step	Guide
Configure `_config.yml` — site identity, skins, collections	Site Configuration
Set up VS Code with extensions and Front Matter CMS	VS Code Setup
Run the site with Docker or native Ruby	Local Development

IT-Journey Quests: Jekyll Fundamentals · YAML Configuration

IT-Journey Docs: Installation Update

External Docs: Jekyll Installation · Jekyll Themes · zer0-mistakes Theme