Add package fetching logic fix proposal

openspec/changes/fix-package-fetch-logic/.openspec.yaml

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+schema: spec-driven
+created: 2026-04-17

openspec/changes/fix-package-fetch-logic/design.md

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+## Context
+
+Current `Resolve` in `pkg/fetch/fetch.go`:
+1. Initialize all packages with `Exists: true`
+2. Check local DB, set `Installed: true` if found
+3. Check sync DBs, set `Installed: false`
+4. Check AUR, set `InAUR: true`
+5. Error if not found anywhere
+
+Bug: wrong default + wrong order + conflates two concerns.
+
+## Goals / Non-Goals
+
+**Goals:**
+- Fix Resolve algorithm to correctly classify packages
+- Separate "available" from "installed" concerns
+
+**Non-Goals:**
+- No new APIs or features
+- No refactoring outside Resolve function
+
+## Decisions
+
+**Decision 1: Start with Exists: false**
+- Default `Exists: false` (unknown) instead of `true`
+- Only set true when confirmed in sync DBs
+
+**Decision 2: Check sync DBs first**
+- Order: sync → local → AUR
+- First determine if package exists (anywhere)
+- Then determine if installed (local only)
+
+**Decision 3: Two-phase classification**
+
+| Phase | Check | Sets |
+|------|-------|-----|
+| 1. Availability | sync DBs | Exists: true/false |
+| 2. Installation | local DB | Installed: true/false |
+| 3. Fallback | AUR | InAUR: true if not in sync |
+
+## Risks / Trade-offs
+
+- Minimal risk: localized fix only
+- Trade-off: slight performance cost (check sync before local) - acceptable for correctness

openspec/changes/fix-package-fetch-logic/proposal.md

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+## Why
+
+The `Resolve` function in `pkg/fetch/fetch.go` has incorrect logic flow. It
+initializes all packages with `Exists: true`, then checks local DB first, then
+sync DBs, then AUR. This wrong order causes incorrect package state
+classification - packages that exist only in AUR may be incorrectly marked as
+found.
+
+## What Changes
+
+- Fix initialization: packages should start with `Exists: false` (unknown), not `true`
+- Fix order: check sync DBs BEFORE local DB to determine availability
+- Separate independent concerns: "available" (sync/AUR) from "installed" (local)
+- All packages must validate: either `Exists: true` or `InAUR: true`
+
+## Capabilities
+
+### New Capabilities
+- `package-resolve-logic`: Correct resolution algorithm for pacman packages
+
+### Modified Capabilities
+- None
+
+## Impact
+
+- `pkg/fetch/fetch.go`: `Resolve` function

openspec/changes/fix-package-fetch-logic/tasks.md

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+## 1. Fix Resolve Function Logic
+
+- [ ] 1.1 Change initialization: start packages with Exists: false instead of true
+- [ ] 1.2 Reorder to check sync DBs BEFORE local DB
+- [ ] 1.3 Separate availability check (sync DBs) from installation check (local DB)
+- [ ] 1.4 Add AUR fallback for packages not in sync DBs
+- [ ] 1.5 Validate all packages have either Exists or InAUR before returning

openspec/specs/package-resolve-logic/spec.md

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+## ADDED Requirements
+
+### Requirement: Package existence check via sync DBs
+
+When resolving packages, the system SHALL first check sync databases (core, extra, multilib) to determine if a package exists in official repositories. If found in sync DBs, `Exists` SHALL be set to true.
+
+#### Scenario: Package found in sync DB
+- **WHEN** package name exists in any sync database
+- **THEN** set `Exists: true`, `InAUR: false`
+
+#### Scenario: Package not found in sync DB
+- **WHEN** package name does not exist in any sync database
+- **THEN** keep `Exists: false` for further lookup
+
+### Requirement: Package installation check via local database
+
+After checking sync DBs, the system SHALL check the local package database to determine if a package is installed. This is independent of existence check.
+
+#### Scenario: Package installed locally
+- **WHEN** package is installed on the system
+- **THEN** set `Installed: true`
+
+#### Scenario: Package not installed locally
+- **WHEN** package is not installed on the system
+- **THEN** set `Installed: false`
+
+### Requirement: AUR fallback check
+
+If package is not found in sync DBs, the system SHALL check the AUR as a fallback.
+
+#### Scenario: Package found in AUR
+- **WHEN** package exists in AUR but not in sync DBs
+- **THEN** set `InAUR: true`
+
+#### Scenario: Package not found anywhere
+- **WHEN** package not in sync DBs, not in local DB, not in AUR
+- **THEN** return error "package not found"
+
+### Requirement: Validation at resolution end
+
+After all checks complete, the system SHALL ensure every package has either `Exists: true` or `InAUR: true`. No package SHALL leave the resolver in an ambiguous state.
+
+#### Scenario: All packages valid
+- **WHEN** all packages resolved successfully
+- **THEN** every package has Exists=true OR InAUR=true