fix: Update dependencies to support GCC 14 / Debian 13

[facundofarias]

Summary

• Relax pinned dependencies (nio4r 2.1.0 → ~> 2.7, timers 4.1.2 → ~> 4.3, rb-readline 0.5.5 → ~> 0.5) to fix compilation failures on Debian 13 / GCC 14
• nio4r 2.1.0 uses a function pointer type (VALUE (*)(void *)) where GCC 14 now requires void * (*)(void *), promoting -Wincompatible-pointer-types from warning to error
• timers 4.3 also drops the hitimes native extension dependency, reducing further compilation risk

Context

A customer on Debian 13 (Ruby 3.3, GCC 14) cannot install the agent at all — gem install deploy-agent fails during native extension compilation.

Test plan

• All 17 RSpec tests pass locally
• RuboCop passes with no offenses
• CI matrix (Ruby 2.7–3.4) passes with the updated dependencies
• Manually verified: gem builds and installs successfully on Fedora (Ruby 3.3, GCC 14, nio4r 2.7.5, timers 4.4.0)
• Manually verified: agent runs correctly after installation

🤖 Generated with Claude Code

[coderabbitai]

Walkthrough

Updated gem dependency version constraints in deploy-agent.gemspec, replacing exact version pins with pessimistic version ranges for nio4r (> 2.7), rb-readline (> 0.5), and timers (~> 4.3). No logic or behavioral changes introduced.

Changes

Cohort / File(s)	Summary
Dependency Version Updates deploy-agent.gemspec, lib/deploy_agent/agent.rb	Updated gem dependency specifications to use pessimistic version ranges instead of exact pins for nio4r, rb-readline, and timers.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related PRs

• Fix Ruby 3.2 File.exists? Deprecation #9: Modifies dependency declarations for the same gems (nio4r, rb-readline, timers) in deploy-agent.gemspec.

Suggested reviewers

• thdurante
• MartaKar

Poem

🐰 A version update hops by,
From pins exact to ranges spry,
Pessimistic constraints in place,
Dependencies embrace their space! 🎉

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: updating dependencies to support GCC 14 and Debian 13, which directly aligns with the PR objectives and the specific dependency version updates in the changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing Touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch add-test-suite-and-multi-ruby-ci

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@lib/deploy_agent/agent.rb`:
- Around line 1-2: Remove the explicit gem activation calls for 'nio4r' and
'timers' from the library file (the lines calling gem 'nio4r', '~> 2.7' and gem
'timers', '~> 4.3') so that dependency resolution is left to the gemspec
(s.add_dependency) and Bundler; simply delete those two gem lines from agent.rb
to avoid runtime gem activation on require and potential version conflicts.