Why we choose MVS?

1. Production-Proven Reliability

The MVS algorithm has been thoroughly validated in large-scale production environments since its introduction into the Go module system in 2018. The widespread adoption of the Go ecosystem demonstrates the stability and predictability of this algorithm when handling complex dependency relationships, providing a solid foundation of confidence for LLAR's adoption of MVS.

2. Semantic Versioning Assumption

LLAR primarily targets mature open-source projects with significant influence. These projects generally adhere to Semantic Versioning or other meaningful versioning schemes, allowing version numbers to reliably indicate the nature of code changes. MVS can only be meaningfully applied under the assumption that most projects follow semantic versioning; without this assumption, its version-selection logic would lose practical significance.

3. Theoretical Basis for Version Conflict Resolution

When MVS encounters a dependency conflict, it selects the maximum version number that satisfies all constraints. This strategy is reasonable under the assumption of semantic versioning:

Case A: Library Follows Forward Compatibility Promise

• Newer versions maintain API forward compatibility
• Selecting the maximum version can satisfy the needs of all dependents
• Result: Build succeeds, dependency conflict resolved

Case B: Library Introduces Breaking Changes

• Newer versions introduce incompatible API changes
• Different dependents rely on mutually incompatible APIs
• Result: Compilation fails, which is the correct behavior – because there are two mutually exclusive requirements, inherently unsolvable
• Manual intervention is required at this point: upgrade dependent code to adapt to the new API, or downgrade to a compatible version

Case C: Version Number Upgraded but New API Not Used

• A dependent declares a dependency on a newer version but does not actually use the new API
• As long as the API signature remains unchanged, using the maximum version should not theoretically cause compatibility issues
• If the API signature changes, it degenerates into Case B (mutually exclusive requirements)

Both case B and case C illustrate scenarios where a library does not fully follow a forward-compatibility promise.

Even without using the MVS algorithm to automatically resolve dependencies, such situations are almost unsolvable in real-world builds. Manual intervention typically involves downgrading one of the conflicting packages to satisfy the build, but this often contradicts the requirements of the dependent project.

The issue contains rationale for MVS but names no files, tests, or entry points and does not state a concrete change. Start by locating MVS and dependency-resolution references in LLAR and checking whether this rationale is already documented. A clear definition of done requires deciding whether to record this decision or revise the approach.