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Runtime bundled-library drift

Ruby 3.4 mutex_m bundled library removed default gem transitive library crashes initialization

A transitive library crashes during initialization on a clean Ruby 3.4 install.

Ruby 3.4RubyRuntime bundled-library driftruby34

Agent Quick Fix

Repair against the current Ruby 3.4 contract, then keep the change narrow and source-backed.

Product: Ruby 3.4
Current-contract area: `mutex_m` implicit dependency disappears
Likely root cause: A transitive library crashes during initialization on a clean Ruby 3.4 install.
Repair direction: Verifier checks an explicit dependency or supported replacement and a clean install.

Symptom

A transitive library crashes during initialization on a clean Ruby 3.4 install.

Why This Happens

A library was historically part of the default runtime install but is now only bundled/optional, so project dependency files may not mention it.

Common Wrong Fixes

  • Changing local code without checking the current external contract.
  • Retrying the same install, build, or API call with no version/source change.
  • Applying a broad unsafe bypass when a narrow compatibility fix is available.

Codex Search Keywords

These are the search terms observed in a neutral Codex validation run for this failure shape.

Ruby 3.4 mutex_m bundled library removed default gem transitive library crashes initialization
Ruby 3.4 mutex_m gem bundled gems changelog
Ruby 3.4 NEWS bundled gems mutex_m
Ruby 3.4.0 Released default gems bundled gems logger mutex_m drb
"mutex_m" "Ruby 3.4" "LoadError"
"mutex_m" "Gemfile" "Ruby 3.4"
https://stdgems.org/3.4.0/
'mutex_m' in https://stdgems.org/3.4.0/
https://docs.ruby-lang.org/en/3.4/NEWS_md.html
'mutex_m' in https://docs.ruby-lang.org/en/3.4/NEWS_md.html
drb 2.2.1 gemspec mutex_m dependency
https://rubygems.org/gems/drb/versions/2.2.1
https://rubygems.org/api/v2/rubygems/drb/versions/2.2.1.json
rubygems api drb 2.2.1 dependencies mutex_m
https://raw.githubusercontent.com/ruby/drb/master/drb.gemspec
https://raw.githubusercontent.com/ruby/drb/v2.2.1/lib/drb/drb.rb
"require 'mutex_m'" "ruby/drb" "drb.rb"
https://github.com/ruby/drb/blob/v2.2.1/lib/drb/drb.rb

Source Trail

GitHub source file/reference: