Breaking change migration: CTBase 0.16.4 → 0.17.0

[ocots]

See issue #403 for details. This PR tracks the breaking change migration from v0.16.4 to v0.17.0.

[github-actions]

Breakage test results
Date: 2026-01-17 13:45:28

Name	Latest	Stable
CTDirect	compat: v0.16.4	compat: v0.16.4
CTFlows	compat: v0.16.4	compat: v0.16.4
CTModels	compat: v0.17.4	compat: v0.17.4
CTParser	compat: v0.17.4	compat: v0.17.4
OptimalControl	compat: v0.16.4	compat: v0.16.4

[ocots]

🎉 Breaking Change Migration - Excellent News!

Summary

Package: CTBase v0.16.2 → v0.17.0
Status: ✅ All packages compatible - No breaking changes!
Complexity: LOW (was initially assessed as HIGH)

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Breakage Test Results

Testing with beta versions (CTModels v0.6.10-beta and CTParser v0.7.3-beta) confirms that all packages work with CTBase v0.17.0:

Package	Latest	Stable	Status
CTModels v0.6.10-beta	✅	✅	Compatible
CTParser v0.7.3-beta	✅	✅	Compatible
CTDirect v0.17.4	✅	✅	Compatible
CTFlows v0.8.9	✅	✅	Compatible
OptimalControl v1.1.6	✅	✅	Compatible

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Migration Strategy

Simplified approach: Only compat widening needed!

Packages to Update

1. CTDirect v0.17.4 → v0.17.5 (patch)

   • Widen compat: CTBase = "0.16, 0.17"

2. CTFlows v0.8.9 → v0.8.10 (patch)

   • Widen compat: CTBase = "0.16, 0.17"

3. OptimalControl v1.1.6 → v1.1.7 (patch)

   • Widen compat: CTBase = "0.16, 0.17"

No code changes required - only Project.toml compat updates!

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Beta Versions

Beta versions were created to test the migration independently:

• CTModels v0.6.10-beta - Registered in ct-registry ✅
• CTParser v0.7.3-beta - Registered in ct-registry ✅

These beta versions confirmed that CTBase v0.17.0 doesn't break any packages. They can remain in ct-registry for reference but are not required for the production migration.

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Next Steps

1. ✅ Breakage tests complete
2. ✅ Beta versions created and tested
3. 📝 Generate action plan
4. 🚀 Execute simple compat widening (1-2 days)

Estimated completion: Much faster than initially expected!

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References

• Setup report: reports-breaking/2026-01-16-ctbase-0.17.0/setup.md
• Issue: Breaking change migration: CTBase 0.16.4 → 0.17.0 #403
• Branch: breaking/ctbase-0.17

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Initial assessment: Complex migration with cascade
Actual result: ✅ Simple migration - all compatible!

The beta version strategy proved its value by allowing us to test independently and discover this excellent news! 🎉