trying to pin problematic gems to known working versions.

Next step though, is to downgrade ruby too.
AI gave me these versions by reading release notes and known issues. amazing.

Author: dcolebatch

Gemfile

@@ -8,6 +8,10 @@ group :jekyll_plugins do
 end
 
 # Pinning problematic gems to compatible versions
-gem 'commonmarker', '~> 0.23.9'
-gem 'unf_ext', '~> 0.0.8.1'
-gem 'eventmachine', '~> 1.2.6'
+gem "commonmarker", "~> 0.23.8"
+gem "unf_ext", "~> 0.0.7.7"
+gem "eventmachine", "~> 1.2.5"
+gem "http_parser.rb", "~> 0.6.0"
+gem "racc", "~> 1.5.2"
+
+gem "github-pages", "232" # or whatever version you're using

netlify.toml

@@ -6,11 +6,5 @@
   command = "bundle install && bundle exec jekyll build"
     publish = "_site"
 
-[build.processing]
-  skip_processing = true
-
-[build.lifecycle]
-  onPreBuild = "echo 'onPreBuild lifecycle event started' && uname -a && gcc --version && sudo apt-get update && sudo apt-get install -y build-essential"
-
 [[plugins]]
   package = "@netlify/plugin-ruby-bundler"