internal/pkg: hold artifact in DCE

This is significantly slower but enables much better error reporting.

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

internal/pkg/pkg.go

@@ -1485,8 +1485,8 @@ func (c *Cache) Cure(a Artifact) (
 
 // CureError wraps a non-nil error returned attempting to cure an [Artifact].
 type CureError struct {
-	Ident unique.Handle[ID]
-	Err   error
+	A   Artifact
+	Err error
 }
 
 // Unwrap returns the underlying error.
@@ -1499,22 +1499,22 @@ 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[unique.Handle[ID]]*CureError) {
+func (e *DependencyCureError) unwrapM(me map[Artifact]*CureError) {
 	for _, err := range *e {
-		if _, ok := me[err.Ident]; ok {
+		if _, ok := me[err.A]; ok {
 			continue
 		}
 		if _e, ok := err.Err.(*DependencyCureError); ok {
 			_e.unwrapM(me)
 			continue
 		}
-		me[err.Ident] = err
+		me[err.A] = err
 	}
 }
 
 // unwrap recursively expands and deduplicates underlying errors.
 func (e *DependencyCureError) unwrap() DependencyCureError {
-	me := make(map[unique.Handle[ID]]*CureError)
+	me := make(map[Artifact]*CureError)
 	e.unwrapM(me)
 	errs := slices.AppendSeq(
 		make(DependencyCureError, 0, len(me)),
@@ -1522,8 +1522,9 @@ func (e *DependencyCureError) unwrap() DependencyCureError {
 	)
 
 	var identBuf [2]ID
+	ir := NewIR()
 	slices.SortFunc(errs, func(a, b *CureError) int {
-		identBuf[0], identBuf[1] = a.Ident.Value(), b.Ident.Value()
+		identBuf[0], identBuf[1] = ir.Ident(a.A).Value(), ir.Ident(b.A).Value()
 		return slices.Compare(identBuf[0][:], identBuf[1][:])
 	})
 
@@ -1548,8 +1549,11 @@ func (e *DependencyCureError) Error() string {
 	}
 	var buf strings.Builder
 	buf.WriteString("errors curing dependencies:")
+	ir := NewIR()
 	for _, err := range errs {
-		buf.WriteString("\n\t" + Encode(err.Ident.Value()) + ": " + err.Error())
+		buf.WriteString("\n\t" +
+			reportName(err.A, ir.Ident(err.A)) + ": " +
+			err.Error())
 	}
 	return buf.String()
 }
@@ -2082,7 +2086,7 @@ func (pending *pendingArtifactDep) cure(c *Cache) {
 	}
 
 	pending.errsMu.Lock()
-	*pending.errs = append(*pending.errs, &CureError{c.Ident(pending.a), err})
+	*pending.errs = append(*pending.errs, &CureError{pending.a, err})
 	pending.errsMu.Unlock()
 }