Compatibility Matrix (Vitte Version Gate)

This matrix is ​​the compatibility source for make version-compatibility-gate.

Axes version

• Language version: 0.2
• Stdlib version: 2.0
• MIR version: 1.0
• Diagnostics version: 1.1
• Sysroot version: 2026.1
• Package manifest version: 1.0
• Minimum supported manifest version: 1.0
• Supported editions: 2025, 2026

Gate Policy

Build fails when one of these conditions happens:

• stdlib incompatible with requested language/version tuple
• sysroot incompatible with compiler declared sysroot version
• old cache not invalidated after MIR or diagnostics schema bump
• manifest version newer than supported parser contract
• diagnostics changes shipped without migration policy update

Migration Policy Hooks

Any diagnostics schema or message contract bump must include:

• migration notes in CHANGELOG.md
• updated compatibility matrix entry
• migration tool behavior verification via make migration-system-check