Wist 0.1.0-alpha.7 candidate stability

UniversalToolchain.Wist 0.1.0-alpha.7 is the current source/release candidate for integration review. It is not published on NuGet.org and is not a stable 1.0 compatibility contract. The package currently exercised from NuGet.org remains 0.1.0-alpha.1.

Reviewed hardening surface

The canonical architecture remains:

LanguageDefinition
    -> LanguageCompiler
    -> immutable LanguagePlan
    -> LanguageRuntime
    -> exact planned implementations

LanguageCompiler.Compile(...) remains the only public planner. LanguageRuntime materializes the immutable plan and does not select semantics, and WistEngine does not perform a second planning pass.

The alpha.7 hardening candidate adds or tightens:

• a typed LanguageBuildRuntime capability so execution-only runtimes do not advertise artifact-build operations they cannot perform;
• construction rollback that preserves the primary exception and its stack while retaining cleanup failures separately;
• a Wist failure taxonomy that distinguishes expected user/policy/unsupported failures from infrastructure/internal faults and fails fast for the latter;
• explicit same-instance Wist concurrency behavior: overlapping operations are rejected instead of being serialized by an undocumented lock;
• source-retention modes Full, HashAndIdentity and None, plus separate developer versus safe consumer diagnostic exposure;
• deterministic CI required-workflow ownership and fail-closed aggregate behavior;
• an evidence-backed physical runtime-closure classification without introducing a second package/runtime topology.

Package candidate matrix

The source tree defines these unpublished candidate identities:

Package	Source candidate
UniversalToolchain.Language.Abstractions	0.3.0-alpha.4
UniversalToolchain.FeatureSdk	0.3.0-alpha.4
UniversalToolchain.LanguageSdk	0.3.0-alpha.5
UniversalToolchain.Runtime	0.3.0-alpha.5
UniversalToolchain.LanguageAuthoring	0.3.0-alpha.5
UniversalToolchain.Testing	0.3.0-alpha.5
UniversalToolchain.Templates	0.3.0-alpha.5
UniversalToolchain.Wist.LanguagePack	0.3.0-alpha.6
UniversalToolchain.Wist	0.1.0-alpha.7

These version changes reserve new identities for changed package payloads, including generated dependency metadata and the ut-language template's package references. They do not publish or promote any package.

Public compatibility notes

The Wist facade adds typed failure, diagnostic-exposure and source-retention information. The reviewed Wist public API delta contains 23 intentional additions and no removals relative to the previous facade snapshot.

Generic runtime artifact-build callers should retain the result of the component-source factory as LanguageBuildRuntime (or var) when they need Build, ExecuteBuilt or GetBuiltArtifactValue. Execution-only code continues to use LanguageRuntime.

Low-level variable binding continues to expose the reviewed top-level InvalidOperationException family. A typed inner binding marker lets the Wist facade classify the same expected authoring failure as UserInput without treating arbitrary InvalidOperationException instances as invalid formulas.

Privacy and concurrency boundary

HashAndIdentity stores a deterministic source hash and length instead of raw source. None stores neither raw source nor its hash in WistProgramMetadata. These policies are retention choices, not secure secret scrubbing guarantees: source may still exist transiently in caller/runtime memory or other application telemetry.

One WistEngine instance is not advertised as concurrently reentrant. Overlapping facade operations on the same instance fail fast. Use separate engine instances for independent concurrent operation streams. This is separate from disposal/lifetime coordination.

Verification boundary

The source tree declares an exact repository test manifest of 1,324 tests across the canonical suites and keeps the existing benchmark smoke, PlanFuzz regression, architecture guards/mutants, package-surface and clean-consumer gates. The baseline-bearing package gate is required because package payload identities changed.

This document does not claim those gates are green for the final revision until the exact final commit has completed them. The pinned verification snapshot and the integration-review report are authoritative for the exact revision that was actually checked.

Not promised

• publication of 0.1.0-alpha.7 or any related package;
• automatic merge or release promotion;
• OS/process sandboxing;
• secure wiping of source text from managed process memory;
• concurrent reentrancy of a single WistEngine instance;
• compatibility with every future alpha;
• universal performance superiority over handwritten C#;
• removal of semantic-only assemblies from the current monolithic Wist package closure.

Promotion rule

Do not describe this candidate as the published package until:

1. the exact candidate revision passes the full baseline-bearing package gate and required CI suite;
2. an explicit release/publish decision is made separately;
3. the exact package is actually published;
4. the clean-room NuGet.org smoke succeeds for the published identity;
5. eng/documentation-release-state.json promotes publishedVersion;
6. public installation commands and evidence links pass the documentation release-state checks and mutants.