Logging at level: debug Configuration file: /github/workspace/./_config.yml GitHub Pages: github-pages v228 GitHub Pages: jekyll v3.9.3 Theme: jekyll-theme-primer Theme source: /usr/local/bundle/gems/jekyll-theme-primer-0.6.0 Requiring: jekyll-github-metadata Requiring: jekyll-seo-tag Requiring: jekyll-coffeescript Requiring: jekyll-commonmark-ghpages Requiring: jekyll-gist Requiring: jekyll-github-metadata Requiring: jekyll-paginate Requiring: jekyll-relative-links Requiring: jekyll-optional-front-matter Requiring: jekyll-readme-index Requiring: jekyll-default-layout Requiring: jekyll-titles-from-headings GitHub Metadata: Initializing... Source: /github/workspace/. Destination: /github/workspace/./_site Incremental build: disabled. Enable with --incremental Generating... EntryFilter: excluded /README.hyde.md EntryFilter: excluded /TODO.md EntryFilter: excluded /LICENSE.hyde.md Generating: JekyllOptionalFrontMatter::Generator finished in 0.000130133 seconds. Generating: JekyllReadmeIndex::Generator finished in 0.001329565 seconds. Generating: Jekyll::Paginate::Pagination finished in 3.597e-06 seconds. Generating: JekyllRelativeLinks::Generator finished in 0.00098996 seconds. Generating: JekyllDefaultLayout::Generator finished in 0.000467023 seconds. Generating: JekyllTitlesFromHeadings::Generator finished in 3.0316e-05 seconds. Rendering: 404.html Pre-Render Hooks: 404.html Rendering Liquid: 404.html Rendering Markup: 404.html Rendering Layout: 404.html Layout source: site GitHub Metadata: Generating for gapdays/gapdays2024-spring GitHub Metadata: Calling @client.pages("gapdays/gapdays2024-spring", {}) Rendering: index.md Pre-Render Hooks: index.md Rendering Liquid: index.md Rendering Markup: index.md Requiring: kramdown-parser-gfm Rendering Layout: index.md Layout source: site Rendering: location.md Pre-Render Hooks: location.md Rendering Liquid: location.md Rendering Markup: location.md Rendering Layout: location.md Layout source: site Rendering: participants.md Pre-Render Hooks: participants.md Rendering Liquid: participants.md github-pages 228 | Error: Liquid error (line 1): Cannot sort a null object.