v0.18.0

Den v0.18 Release Notes

✨ Major Features

1. Gen-schema entity port + resolver/delivery unification (#563)

Five-part stabilization reaching 1023/1023 tests (from 825 at branch start):

• Entity schema refactor: den.schema migrates to gen-schema's mkSchemaOption/mkSchemaEntryType. Entities own id_hash via mkInstanceType. Flat declaration forms (den.hosts.igloo = {}, den.homes."tux@igloo" = {}) coexist with legacy two-level nesting.
• Isolation + delivered-child host: microvm guests. Kind-level isolated marker, re-instantiating payload delivery, projected hasAspect re-keyed by entity id_hash (fixes nested host false-negatives).
• Resolver decoupling: Pure arg classifier over schema entity DAG. Removes host/user-specific machinery from fx resolver core. Fixes host-scope { user } homeManager aspects leaking to all users (#609).
• Delivery-edge unification: Nine ad-hoc mechanisms collapse to one (S, T, P, M) edge algebra. New deliver { from; to; at ?[]; mode ? "merge" } primitive; route and provides retained as thin shims. One toposorted edge-fold per root.
• Constraint registry unification + sibling-exclusion fixes: sibling excludes no longer leak across entities. Unified scope+ancestor constraint lookup; late-policy dispatch scopes to emitting sibling.

Breaking change: Entity-arg binding now scoped (inert if not in-context). Cross-entity delivery via provides/policy only. Documented in explanation/parametric.mdx.

2. Synthesize host identity for standalone user@host homes (#605)

Standalone home user@host now resolves host-keyed config (provides.<host>, policy.when ({ host })) without declaring the host or instantiating platform builder. Minimal { name = hostName } identity synthesized; declared host still wins.

Fixes crash in related include-return path: aspects returning include-effect lists (e.g. lib.optional cond (policy.include {...})) now normalized (lists flattened, effects pass through).

3. In-context hasAspect honors projected scope state (#602)

.hasAspect inside parametric bodies now answers projected membership ("delivered into this scope") vs structural tree. Registry query (den.hosts.….users.tux.hasAspect) stays structural. Per-scope pathSetByScope recorded; zero extra pipeline runs.

🐛 Major Fixes

Resolver & delivery pipeline

• Sibling policy.when guard dedup collision (#603): Guards compile to anonymous aspects; dedup now indices synthetic names and chains payloads, preventing second guard's content vanishing.
• Spawn subtree routes (#603): Parent pipeline routes now apply to spawned resolution; user-scope route no longer skipped in spawn re-entry.
• Multi-def forwarded identity (#603): Multi-def namespace children now tagged with __provider, fixing double-emission from multi-path inclusion.
• Guarded route crashes (#600): intoPath alias honored; guarded empty-path routes now skip cleanly with optionalAttrs (not mkIf).
• Positional context functions in includes (#578): ctx: ... functions (empty args) now routed to parametric compile and called with full scope context, not silently dropped.

Forward routing & class merging

• Forwarded content overwritten across scopes (#583): Root content in complex forwards no longer filtered to @default-only when not an entity-owned class. Fixes cross-scope aggregation (e.g. atuin flags merging).
• Route wrapping merge semantics (#574): Multiple aspects defining same flake class no longer clobber. Routes toposorted (producers before consumers); mergeableType deep-merges instead of shallow //.
• Order simple routes before forwards (#584): Routes applied in correct order; custom forwards consume class content correctly.

Config & module handling

• Don't force aspect content during key classification (#580): Lazy instantiation preserved in compile-static; no forced evaluation during structural key walk.
• Resolve positional functions with scope context (#578): Direct lambda detection + ctxFromHandlers call instead of fx.bind.fn.
• Null coercion in warning messages (#576): Explicit if check replaces or; no more cannot coerce null on multi-system homes with null system.

Entity & output handling

• Disambiguate multi-system homes (#565): Same user on multiple systems auto-qualified @system (homeConfigurations."ben@x86_64-linux" / homeConfigurations."ben@aarch64-darwin"). Single-system homes keep plain name.
• Correct flake output include schema kind (#587): Example corrected to flake-system (not non-existent flake-packages).
• Remove __denTest hack (#571): Test harness cleanup.
• Missing host class in batteries (#606): host ? class check prevents unfree battery crash when host lacks class.

Schema & validation

• Flattening default den.schema (#616): Fixes Lix runtime (other nix runtimes) unable to merge multiple attrs same name in different brackets.

🎨 Refactors & Chores

• Extract diagram library to sini/den-diagram (#564): nix/lib/diag/ → den-diagram repo. Den keeps only capture.nix (fx tracing). Templates (diagram-demo, fleet-demo) use two-step pattern. Den CI has zero den-diagram dependency.
• Organize tests: public-api/internal-api/deadbugs (#592): Test suite restructured; CI test org documented.
• Backport aspect-pipeline fixes (#589): Cherry-picks + one net-new (namespace root _ bundle). Namespace-root _ exposes container-level aspects (flat map, no recursion).
• Performance: break closure chains and lazy instantiation (#579): Backport; reduced evaluation overhead.
• CI: bump nix-effects to den branch (#529): Dependency update.

📖 Documentation

• Remove deprecated link (#612): Archived repository pattern removed.
• Update links & README (#595, #594): Examples simplified, links corrected.
• Update docs from source (#593): Docs refreshed.
• Fix typos (#597).
• GH-pages robustness (#591): Artifact listing paginates; no longer caps at 30 (silent truncation).

✅ CI & Testing

• Live label queries, real allow-ci gating (#607): Label checks now query API (see re-run labels); ci-deep/flake-check actually gated; main builds never cancelled; non-draft skip cleanly on docs-only PRs; approved reviews only re-trigger CI.

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What's Changed

• fix: disambiguate multi-system homes targeting same homeConfigurations output by @sini in #565
• fix: remove __denTest hack by @vic in #571
• ci: bump nix-effects to den branch by @vic in #529
• fix: route wrapping merge semantics and forward ordering by @sini in #574
• fix: null coercion in disambiguate warning message by @sini in #576
• fix: don't force aspect content during key classification (#580) by @sini in #581
• perf: break closure chains and lazy instantiation backport by @sini in #579
• fix: resolve positional functions in includes with scope context by @sini in #578
• fix: forwarded content overwritten across scopes (#583) by @sini in #585
• fix: correct flake output include to flake-system schema kind by @sini in #587
• fix: backport aspect-pipeline fixes from entity-gen-schema-port by @sini in #589
• fix: order simple routes before forwards that consume their class by @sini in #584
• fix: gh-pages dont fail if no cached versioned docs exist by @vic in #591
• improve: organize tests public-api/internal-api/deadbugs by @vic in #592
• docs: update docs from source by @vic in #593
• docs: update README remove extensive code examples by @vic in #594
• docs: update links by @vic in #595
• refactor: Extract diagram library to sini/den-diagram by @sini in #564
• docs: fix some typos by @quokkbit in #597
• fix: guarded empty-path route skips cleanly; honor intoPath alias by @sini in #600
• feat: in-context hasAspect honors projected (delivered) scope state by @sini in #602
• fix: sibling policy.when guard dedup collision; spawn subtree routes; multi-def forwarded identity by @sini in #603
• fix: move deadbug to proper location by @vic in #604
• feat: synthesize host identity for standalone user@host homes by @sini in #605
• fix: missing host class in batteries by @KP64 in #606
• fix(ci): live label queries, real allow-ci gating, dead triggers by @sini in #607
• fix(docs): Remove deprecated link by @Adda0 in #612
• feat: gen-schema entity port + resolver decoupling + delivery-edge unification by @sini in #563
• fix: flattening default den.schema by @fmway in #616

New Contributors

• @quokkbit made their first contribution in #597
• @KP64 made their first contribution in #606
• @fmway made their first contribution in #616

Full Changelog: v0.17.0...v0.18.0