internal/pkg: deduplicate DCE by ident

This eliminates edge cases where target artifacts do not compare equal.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/pkg.go

@@ -1499,41 +1499,52 @@ func (e *CureError) Error() string { return e.Err.Error() }
 type DependencyCureError []*CureError
 
 // unwrapM recursively expands underlying errors into a caller-supplied map.
-func (e *DependencyCureError) unwrapM(me map[Artifact]*CureError) {
+func (e *DependencyCureError) unwrapM(
+	ir *IRCache,
+	me map[unique.Handle[ID]]*CureError,
+) {
 	for _, err := range *e {
-		if _, ok := me[err.A]; ok {
+		id := ir.Ident(err.A)
+		if _, ok := me[id]; ok {
 			continue
 		}
 		if _e, ok := err.Err.(*DependencyCureError); ok {
-			_e.unwrapM(me)
+			_e.unwrapM(ir, me)
 			continue
 		}
-		me[err.A] = err
+		me[id] = err
 	}
 }
 
 // unwrap recursively expands and deduplicates underlying errors.
-func (e *DependencyCureError) unwrap() DependencyCureError {
-	me := make(map[Artifact]*CureError)
-	e.unwrapM(me)
-	errs := slices.AppendSeq(
-		make(DependencyCureError, 0, len(me)),
-		maps.Values(me),
-	)
+func (e *DependencyCureError) unwrap(ir *IRCache) DependencyCureError {
+	me := make(map[unique.Handle[ID]]*CureError)
+	e.unwrapM(ir, me)
+	type ent struct {
+		id  unique.Handle[ID]
+		err *CureError
+	}
+	errs := make([]*ent, 0, len(me))
+	for id, err := range me {
+		errs = append(errs, &ent{id, err})
+	}
 
 	var identBuf [2]ID
-	ir := NewIR()
-	slices.SortFunc(errs, func(a, b *CureError) int {
-		identBuf[0], identBuf[1] = ir.Ident(a.A).Value(), ir.Ident(b.A).Value()
+	slices.SortFunc(errs, func(a, b *ent) int {
+		identBuf[0], identBuf[1] = a.id.Value(), b.id.Value()
 		return slices.Compare(identBuf[0][:], identBuf[1][:])
 	})
 
-	return errs
+	_errs := make(DependencyCureError, len(errs))
+	for i, v := range errs {
+		_errs[i] = v.err
+	}
+	return _errs
 }
 
 // Unwrap returns a deduplicated slice of underlying errors.
 func (e *DependencyCureError) Unwrap() []error {
-	errs := e.unwrap()
+	errs := e.unwrap(NewIR())
 	_errs := make([]error, len(errs))
 	for i, err := range errs {
 		_errs[i] = err
@@ -1543,13 +1554,13 @@ func (e *DependencyCureError) Unwrap() []error {
 
 // Error returns a user-facing multiline error message.
 func (e *DependencyCureError) Error() string {
-	errs := e.unwrap()
+	ir := NewIR()
+	errs := e.unwrap(ir)
 	if len(errs) == 0 {
 		return "invalid dependency cure outcome"
 	}
 	var buf strings.Builder
 	buf.WriteString("errors curing dependencies:")
-	ir := NewIR()
 	for _, err := range errs {
 		buf.WriteString("\n\t" +
 			reportName(err.A, ir.Ident(err.A)) + ": " +

internal/pkg/pkg_test.go

@@ -1515,6 +1515,8 @@ func TestDependencyCureError(t *testing.T) {
 	makeIdent := func(ident ...byte) pkg.Artifact {
 		var a overrideIdent
 		copy(a.id[:], ident)
+		// does not compare equal
+		a.TrivialArtifact = new(stubArtifact)
 		return a
 	}