# Ruby 3.4 base64 default gem bundled library removed require base64 Gemfile dependency

Status: search-observed
Product: Ruby 3.4
Last verified: 2026-06-25
Canonical HTML: https://gitdocs.org/fix/ruby-3-4-base64-default-gem-bundled-library-removed-require-base64-gemfile-dependency
Machine JSON: https://gitdocs.org/api/fixes/ruby-3-4-base64-default-gem-bundled-library-removed-require-base64-gemfile-dependency.json

## Exact Symptom

See the observed Codex queries below.

## Diagnosis

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

## Fix

```
Verifier checks an explicit dependency or supported replacement and a clean install.
```

## Avoid

- 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.

## Observed Codex Queries

- Ruby 3.4 base64 default gem bundled library removed require base64 Gemfile dependency
- site:stdgems.org base64 Ruby 3.4 default gem bundled gem
- https://stdgems.org/3.4.0/

## Sources

- Ruby 3.4 release: https://www.ruby-lang.org/en/news/2024/12/25/ruby-3-4-0-released/
- Official reference opened by Codex: https://stdgems.org/3.4.0/