fix(harness): fail fast on missing oracle + compare errors against oracle (Round 58)

TASK-144: test-cross-platform-compat.sh now FAILs (not SKIPs) when oracle missing
  - Uses lib/crsqlite-darwin-aarch64.dylib (platform-specific paths)
  - Discovered 2 real failures: resurrection + text newlines

TASK-145: test-schema-evolution.sh now compares errors against oracle
  - No more 'acceptable error' PASS paths
  - Parity verified for dropped/missing column changesets

TASK-147: In progress, first attempt reverted (schema change too broad)
TASK-148: New triage task for compat failures discovered by TASK-144

done

Author: subtleGradient

.tasks/active/TASK-147-cross-open-modification-interoperability.md

@@ -63,6 +63,36 @@ Unify on the Rust/C trigger schema and semantics:
 
 ## Progress Log
 - 2025-12-21: Task created from hard requirement: cross-open modification must work both directions.
+- 2025-12-21: First attempt by subagent failed — changed pks table schema AND trigger SQL but left backfill using old schema, causing "failed to backfill existing rows" error. Changes stashed and reverted.
+- 2025-12-21: **Remains in active** — needs more careful incremental approach.
+
+## Implementation Notes (from failed attempt)
+The first approach tried to:
+1. Change pks table from `(pk, base_rowid, pks BLOB)` to `(__crsql_key, pk_col1, pk_col2, ...)` (Rust/C schema)
+2. Add `crsql_after_insert/update/delete` SQL functions
+3. Change trigger generation
+
+This failed because:
+- The schema change touched too many functions simultaneously (backfill, triggers, changes_vtab, merge)
+- The pks table schema is deeply embedded in the codebase
+- Need incremental approach: first add functions, then change triggers, then verify
+
+## Recommended Approach (incremental)
+1. **Phase 1**: Add `crsql_after_insert/update/delete` functions that work with CURRENT pks schema
+   - These functions should do what the current inline trigger SQL does
+   - Register them in init.zig
+   - Verify existing tests still pass
+
+2. **Phase 2**: Change trigger generation to call these functions
+   - No schema changes yet
+   - Triggers now call helper functions instead of embedding pack_columns
+   - Verify existing tests still pass
+
+3. **Phase 3**: Test cross-open with current schema
+   - Zig can now open Rust/C DBs (has crsql_after_* functions)
+   - But Rust/C still can't open Zig DBs (triggers still use pack_columns)
+   
+4. **Phase 4**: Align pks schema if needed for full bidirectional support
 
 ## Completion Notes
 (Empty until done.)

…schema-evolution-no-acceptable-errors.md …schema-evolution-no-acceptable-errors.md.tasks/active/TASK-145-schema-evolution-no-acceptable-errors.md renamed to .tasks/done/TASK-145-schema-evolution-no-acceptable-errors.md .tasks/active/TASK-145-schema-evolution-no-acceptable-errors.md renamed to .tasks/done/TASK-145-schema-evolution-no-acceptable-errors.md

@@ -4,7 +4,7 @@
 Turn the "acceptable error" paths in `zig/harness/test-schema-evolution.sh` into explicit, stable behavior assertions, so schema-evolution sync does not silently mask real compatibility issues.
 
 ## Status
-- State: active
+- State: done
 - Priority: medium
 
 ## Problem Statement
@@ -35,6 +35,32 @@ This is a potential invalidation surface:
 
 ## Progress Log
 - 2025-12-21: Task created from observed "PASS with SQL logic error" patterns in schema evolution harness.
+- 2025-12-21: Implemented oracle comparison for error paths.
 
 ## Completion Notes
-(Empty until done.)
+### Changes Made
+1. **Added oracle comparison infrastructure**:
+   - `ORACLE_EXT` path detection for Rust/C reference implementation
+   - `run_oracle_sql()` helper with correct entry point (`sqlite3_crsqlite_init`)
+   - `get_actual_error()` helper to filter harmless warnings
+
+2. **Test 2b (dropped column changeset)** now:
+   - Compares Zig error against oracle error
+   - PASS if both error (parity verified)
+   - FAIL if behavior differs (parity gap)
+
+3. **Test 3a (missing column changeset)** now:
+   - Same oracle comparison logic
+   - Clear "PARITY GAP" failure messages if behavior differs
+
+### Key Finding
+Both Zig and the Rust/C oracle return "SQL logic error" for changesets targeting dropped/missing columns. This is **correct parity** - the original test was masking this behind "acceptable error" without verifying consistency.
+
+### Test Results
+```
+PASSED:  12
+FAILED:  0
+SKIPPED: 0
+```
+
+All tests pass with explicit parity verification instead of vague "acceptable error" fallbacks.

.tasks/triage/TASK-148-cross-platform-compat-failures.md

@@ -0,0 +1,44 @@
+# TASK-148 — Fix cross-platform compat test failures (resurrection + text newlines)
+
+## Goal
+Fix the 2 compatibility failures discovered by `zig/harness/test-cross-platform-compat.sh` after it was converted from SKIP to FAIL mode.
+
+## Status
+- State: triage
+- Priority: high
+
+## Problem Statement
+`bash zig/harness/test-cross-platform-compat.sh` now runs (doesn't SKIP) and found 2 real failures:
+
+1. **Test G: Resurrection** — table `sch_test already exists` error during schema evolution sync
+2. **Test M: Text Edge Cases** — text with newlines differs between Zig and Rust/C export
+
+These are Zig implementation bugs, not harness issues.
+
+## Evidence
+```
+WARNING: Rust/C error:
+Error: sqlite3_close() returns 5: unable to close due to unfinalized statements or unfinished backups
+
+FAIL: Text id=5 differs (Zig='line1
+line2', Rust=)
+```
+
+## Files to Modify
+(To be determined during investigation)
+- Likely `zig/src/changes_vtab.zig` or related sync export code
+
+## Acceptance Criteria
+1. `bash zig/harness/test-cross-platform-compat.sh` passes all tests (0 failures)
+2. Text with newlines exports correctly from Zig
+3. Resurrection/schema evolution sync works without "table already exists" errors
+
+## Parent Docs / Cross-links
+- `zig/harness/test-cross-platform-compat.sh`
+- `.tasks/done/TASK-144-cross-platform-compat-no-skip.md` (discovered these)
+
+## Progress Log
+- 2025-12-21: Created from failures discovered by TASK-144 harness fix.
+
+## Completion Notes
+(Empty until done.)

research/zig-cr/92-gap-backlog.md

@@ -1,20 +1,24 @@
 # 92-gap-backlog
 
-> Last updated: 2025-12-20 (Round 53 — TASK-125, TASK-126 complete — schema_alter pk→key + merge resolution fixed)
+> Last updated: 2025-12-21 (Round 58 — TASK-144, TASK-145 complete — harness fail-fast policy)
 
 ## Status
 
 - MVP: ✅ complete (154/154 tests passing)
 - Oracle parity: ✅ **18/18 pass** (all divergences fixed)
-- Cross-open modification compatibility: ❌ gap captured (XO-003/XO-004/XO-006) — see `.tasks/triage/TASK-143-cross-open-modification-compat.md`
+- Cross-open modification compatibility: ❌ **in progress** (XO-003/XO-004/XO-006) — see `.tasks/active/TASK-147-cross-open-modification-interoperability.md`
+- Cross-platform compat tests: ❌ **2 failures discovered** — see `.tasks/triage/TASK-148-cross-platform-compat-failures.md`
+- Harness fail-fast policy: ✅ TASK-144, TASK-145 complete (no more silent SKIPs or "acceptable errors")
 - Zig implementation: `zig/`
 - Canonical task queue: `.tasks/{backlog,active,done}/`
 
 ## Now (next parallel assignments)
 
 All oracle parity tests pass. Zig implementation is wire-compatible with the Rust/C oracle for sync/wire format and read-only cross-open.
 
-A remaining compatibility gap exists for **cross-open modification** (DB created by Zig modified by Rust/C, or vice versa). This is tracked as a first-class gap: `.tasks/triage/TASK-143-cross-open-modification-compat.md`.
+Remaining compatibility gaps:
+- **Cross-open modification** (DB created by Zig modified by Rust/C, or vice versa) — `.tasks/active/TASK-147-cross-open-modification-interoperability.md`
+- **Cross-platform compat failures** (resurrection + text newlines) — `.tasks/triage/TASK-148-cross-platform-compat-failures.md`
 
 ### Hypothesis Invalidation (Done)
 - [x] **TASK-127** — Experimentally invalidate "full parity" hypothesis via fuzzing ✓ `.tasks/done/TASK-127-experimental-parity-invalidation.md`

zig/harness/test-cross-platform-compat.sh

@@ -29,26 +29,21 @@ fi
 # Determine extension paths based on platform
 if [[ "$(uname)" == "Darwin" ]]; then
     ZIG_EXT="$ZIG_DIR/zig-out/lib/libcrsqlite.dylib"
-    # Try multiple locations for Rust/C extension
-    if [[ -f "$REPO_ROOT/lib/crsqlite.dylib" ]]; then
-        RUST_EXT="$REPO_ROOT/lib/crsqlite.dylib"
-    elif [[ -f "$REPO_ROOT/core/dist/crsqlite.dylib" ]]; then
-        RUST_EXT="$REPO_ROOT/core/dist/crsqlite.dylib"
+    # Use local oracle binaries (updated via scripts/update-crsqlite-oracle.sh)
+    ARCH="$(uname -m)"
+    if [[ "$ARCH" == "arm64" ]]; then
+        RUST_EXT="$REPO_ROOT/lib/crsqlite-darwin-aarch64.dylib"
     else
-        echo "SKIP: Rust/C extension not found (need lib/crsqlite.dylib or core/dist/crsqlite.dylib)"
-        echo "Run 'make -C core loadable' or 'npm run bundle-lib' to build it"
-        exit 2
+        RUST_EXT="$REPO_ROOT/lib/crsqlite-darwin-x86_64.dylib"
     fi
 else
     ZIG_EXT="$ZIG_DIR/zig-out/lib/libcrsqlite.so"
-    if [[ -f "$REPO_ROOT/lib/crsqlite.so" ]]; then
-        RUST_EXT="$REPO_ROOT/lib/crsqlite.so"
-    elif [[ -f "$REPO_ROOT/core/dist/crsqlite.so" ]]; then
-        RUST_EXT="$REPO_ROOT/core/dist/crsqlite.so"
+    # Use local oracle binaries (updated via scripts/update-crsqlite-oracle.sh)
+    ARCH="$(uname -m)"
+    if [[ "$ARCH" == "aarch64" ]]; then
+        RUST_EXT="$REPO_ROOT/lib/crsqlite-linux-aarch64.so"
     else
-        echo "SKIP: Rust/C extension not found (need lib/crsqlite.so or core/dist/crsqlite.so)"
-        echo "Run 'make -C core loadable' or 'npm run bundle-lib' to build it"
-        exit 2
+        RUST_EXT="$REPO_ROOT/lib/crsqlite-linux-x86_64.so"
     fi
 fi
 
@@ -59,8 +54,9 @@ if [[ ! -f "$ZIG_EXT" ]]; then
 fi
 
 if [[ ! -f "$RUST_EXT" ]]; then
-    echo "SKIP: Rust/C extension not found at $RUST_EXT"
-    exit 2
+    echo "FAIL: Rust/C oracle not found at $RUST_EXT"
+    echo "Run: ./scripts/update-crsqlite-oracle.sh"
+    exit 1
 fi
 
 echo "Zig extension:    $ZIG_EXT"
@@ -89,7 +85,7 @@ run_zig() {
 run_rust() {
     local db="$1"
     local sql="$2"
-    nix run nixpkgs#sqlite -- "$db" -cmd ".load $RUST_EXT" "$sql" 2>"$ERRFILE" || true
+    nix run nixpkgs#sqlite -- "$db" -cmd ".load $RUST_EXT sqlite3_crsqlite_init" "$sql" 2>"$ERRFILE" || true
 }
 
 # Check for blocking errors (functions not implemented)
@@ -284,7 +280,7 @@ echo "Updated apple value in Rust/C: $RUST_APPLE"
 echo ""
 echo "Step 2: Exporting changes from Rust/C database..."
 
-nix run nixpkgs#sqlite -- "$DB_RUST" -cmd ".load $RUST_EXT" "
+nix run nixpkgs#sqlite -- "$DB_RUST" -cmd ".load $RUST_EXT sqlite3_crsqlite_init" "
     SELECT 'CHANGE:' || 
         [table] || '|' || 
         quote(pk) || '|' || 
@@ -469,7 +465,7 @@ run_rust "$DB_RUST" "DELETE FROM items WHERE id = 5;"
 check_blocked "Rust/C"
 
 # Export delete change
-nix run nixpkgs#sqlite -- "$DB_RUST" -cmd ".load $RUST_EXT" "
+nix run nixpkgs#sqlite -- "$DB_RUST" -cmd ".load $RUST_EXT sqlite3_crsqlite_init" "
     SELECT 'CHANGE:' || 
         [table] || '|' || 
         quote(pk) || '|' || 
@@ -599,7 +595,7 @@ else
 fi
 
 # Step 4: Sync resurrection back to Zig
-nix run nixpkgs#sqlite -- "$DB_RUST_RES" -cmd ".load $RUST_EXT" "
+nix run nixpkgs#sqlite -- "$DB_RUST_RES" -cmd ".load $RUST_EXT sqlite3_crsqlite_init" "
     SELECT 'CHANGE:' || 
         [table] || '|' || 
         quote(pk) || '|' ||