t4929: Fix Bash 3.2 bad substitution in config_get

[marcusquinn]

Summary

• replace Bash 4-style indirect expansion (${!name:-}) in config_get with a Bash 3.2-safe check and read path
• preserve env override precedence while avoiding bad substitution when pulse-wrapper.sh sources config-helper.sh on macOS /bin/bash
• validated with shellcheck and a /bin/bash source repro

Closes #4929

Verification

• shellcheck .agents/scripts/config-helper.sh
• /bin/bash -lc 'source .agents/scripts/pulse-wrapper.sh'
• /bin/bash -lc 'source .agents/scripts/config-helper.sh; AIDEVOPS_MAX_WORKERS_CAP=11; config_get orchestration.max_workers_cap 8'

Summary by CodeRabbit

• Bug Fixes
  • Improved environment variable override handling to properly distinguish between unset and set (empty) variables, ensuring more reliable configuration management.

[gemini-code-assist]

Warning

You have reached your daily quota limit. Please wait up to 24 hours and I will start processing your requests again!

[coderabbitai]

Caution

Review failed

Pull request was closed or merged during review

Walkthrough

This change fixes Bash 3.2 compatibility in the config helper by replacing incompatible indirect expansion syntax ${!env_var:-} with a safe parameter expansion check pattern that detects whether an environment variable is explicitly set before reading its value.

Changes

Cohort / File(s)	Summary
Bash 3.2 Compatibility Fix .agents/scripts/config-helper.sh	Modified config_get function to replace Bash 4.0+ indirect expansion syntax with Bash 3.2-compatible checks using ${!env_var+x} parameter expansion. Now properly distinguishes between unset and set (potentially empty) environment variables without triggering "bad substitution" errors.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

From macOS 3.2 comes a gentle plea,
"Expand my variables, safely!" 🐚
Parameter checks with finesse align,
Bash compatibility—a perfect design,
Pulse keeps dancing, workers aligned,
Zero technical debt, perfectly refined. ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the main fix: replacing Bash 4 syntax with Bash 3.2-compatible code in config_get function.
Linked Issues check	✅ Passed	The PR successfully addresses all linked issue objectives: replaces ${!env_var:-} with Bash 3.2-safe logic at all three locations, preserves env-var override precedence, and validates ShellCheck compatibility.
Out of Scope Changes check	✅ Passed	Changes are strictly confined to config-helper.sh with focused updates to the config_get function's environment variable handling, directly addressing the Bash 3.2 compatibility issue.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch bugfix/issue-4929-bash32-config-get

📝 Coding Plan

• Generate coding plan for human review comments

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[github-actions]

🔍 Code Quality Report

�[0;35m[MONITOR]�[0m Code Review Monitoring Report

�[0;34m[INFO]�[0m Latest Quality Status:
SonarCloud: 0 bugs, 0 vulnerabilities, 362 code smells

�[0;34m[INFO]�[0m Recent monitoring activity:
Sun Mar 15 05:25:00 UTC 2026: Code review monitoring started
Sun Mar 15 05:25:01 UTC 2026: SonarCloud - Bugs: 0, Vulnerabilities: 0, Code Smells: 362

📈 Current Quality Metrics

• BUGS: 0
• CODE SMELLS: 362
• VULNERABILITIES: 0

Generated on: Sun Mar 15 05:25:03 UTC 2026

---

Generated by AI DevOps Framework Code Review Monitoring

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[marcusquinn]

Closing in favour of PR #4931 (branch bugfix/t1491-bash32-config-helper, author: alex-solovyev) which is more comprehensive — fixes 3 locations in config-helper.sh vs this PR's 1 location. Both PRs have green CI. Supervisor merging #4931.