Revert "upgrade to Jekyll 4"

This reverts commit c3329e5c7882e991aa1850894f4ba1d9d6030248.

OMFG: https://github.com/jekyll/github-metadata/issues/242

6 files changed, 32 insertions, 25 deletions

diff --git a/.gitignore b/.gitignore
index 0eae378..1e06029 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,2 @@
-/.jekyll-cache/
 _site/
 .wget/
diff --git a/Gemfile b/Gemfile
index af4984b..3915562 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,10 @@
 source 'https://rubygems.org'
-gem 'jekyll', '~> 4'
+gem 'jekyll', '~> 3'
 
 gem 'jekyll-github-metadata'
 gem 'jekyll-paginate'
 gem 'jekyll-remote-theme'
 gem 'jekyll-tidy'
+# Why is this not a dependency of Jekyll? Considering that without
+# kramdown-parser-gfm, Jekyll will error out.
+gem 'kramdown-parser-gfm'
diff --git a/Gemfile.lock b/Gemfile.lock
index e139334..7431c12 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -9,32 +9,30 @@ GEM
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
     eventmachine (1.2.7)
-    faraday (2.6.0)
+    faraday (2.5.2)
       faraday-net_http (>= 2.0, < 3.1)
       ruby2_keywords (>= 0.0.4)
-    faraday-net_http (3.0.1)
+    faraday-net_http (3.0.0)
     ffi (1.15.5)
     forwardable-extended (2.6.0)
     htmlbeautifier (1.4.2)
     htmlcompressor (0.4.0)
     http_parser.rb (0.8.0)
-    i18n (1.12.0)
+    i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jekyll (4.2.2)
+    jekyll (3.9.2)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
-      i18n (~> 1.0)
-      jekyll-sass-converter (~> 2.0)
+      i18n (~> 0.7)
+      jekyll-sass-converter (~> 1.0)
       jekyll-watch (~> 2.0)
-      kramdown (~> 2.3)
-      kramdown-parser-gfm (~> 1.0)
+      kramdown (>= 1.17, < 3)
       liquid (~> 4.0)
-      mercenary (~> 0.4.0)
+      mercenary (~> 0.3.3)
       pathutil (~> 0.9)
-      rouge (~> 3.0)
+      rouge (>= 1.7, < 4)
       safe_yaml (~> 1.0)
-      terminal-table (~> 2.0)
     jekyll-github-metadata (2.15.0)
       jekyll (>= 3.4, < 5.0)
       octokit (~> 4.0, != 4.4.0)
@@ -44,8 +42,8 @@ GEM
       jekyll (>= 3.5, < 5.0)
       jekyll-sass-converter (>= 1.0, <= 3.0.0, != 2.0.0)
       rubyzip (>= 1.3.0, < 3.0)
-    jekyll-sass-converter (2.2.0)
-      sassc (> 2.0.1, < 3.0)
+    jekyll-sass-converter (1.5.2)
+      sass (~> 3.4)
     jekyll-tidy (0.2.2)
       htmlbeautifier
       htmlcompressor
@@ -60,7 +58,7 @@ GEM
     listen (3.7.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
-    mercenary (0.4.0)
+    mercenary (0.3.6)
     octokit (4.25.1)
       faraday (>= 1, < 3)
       sawyer (~> 0.9)
@@ -75,24 +73,25 @@ GEM
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
     safe_yaml (1.0.5)
-    sassc (2.4.0)
-      ffi (~> 1.9)
+    sass (3.7.4)
+      sass-listen (~> 4.0.0)
+    sass-listen (4.0.0)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
     sawyer (0.9.2)
       addressable (>= 2.3.5)
       faraday (>= 0.17.3, < 3)
-    terminal-table (2.0.0)
-      unicode-display_width (~> 1.1, >= 1.1.1)
-    unicode-display_width (1.8.0)
 
 PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
-  jekyll (~> 4)
+  jekyll (~> 3)
   jekyll-github-metadata
   jekyll-paginate
   jekyll-remote-theme
   jekyll-tidy
+  kramdown-parser-gfm
 
 BUNDLED WITH
    2.3.13
diff --git a/_config.yml b/_config.yml
index 352d373..ff67597 100644
--- a/_config.yml
+++ b/_config.yml
@@ -6,13 +6,16 @@ show_drafts: true
 strict_front_matter: true
 
 exclude:
+  - Gemfile
+  - Gemfile.lock
   - Makefile
   - README.md
+  - vendor/
 
 collections:
   notes:
     output: true
-    # I want the "natural" sorting (a.k.a. whatever the sort_natural filter does).
+    # Jekyll 4.0 or later:
     #sort_by: title
 
 defaults:
@@ -55,7 +58,7 @@ repository: egor-tensin/blog
 # jekyll-paginate
 paginate: 10
 # jekyll-remote-theme
-remote_theme: egor-tensin/jekyll-theme@425d20d2001d87eff0e6aa3c605bf30ff2063f60
+remote_theme: egor-tensin/jekyll-theme@2dc87131123afaa1716c87dd02164b33059ad2b8
 
 # Theme settings
 settings:
diff --git a/_includes/notes.html b/_includes/notes.html
index 59173cf..4b739af 100644
--- a/_includes/notes.html
+++ b/_includes/notes.html
@@ -1,3 +1,6 @@
+{% comment %}
+  Sorting can be done in _config.yml with Jekyll 4.0 or later.
+{% endcomment %}
 {% assign note_list = site.notes | sort_natural: 'title' %}
 <div class="list-group wide-enough">
   {% assign h = 'h4' %}
diff --git a/_posts/2020-05-20-makefile-escaping.md b/_posts/2020-05-20-makefile-escaping.md
index 8ee6ec0..4190fff 100644
--- a/_posts/2020-05-20-makefile-escaping.md
+++ b/_posts/2020-05-20-makefile-escaping.md
@@ -38,7 +38,7 @@ TL;DR
 Visit [this page] for an all-in-one Makefile template.
 {: .alert .alert-info }
 
-[this page]: {% link _notes/makefile.md %}
+[this page]: {{ site.baseurl }}{% link _notes/makefile.md %}
 
 * Put the prologue above at the top of your Makefile.
 * Quote command arguments in Makefiles using single quotes `'`.