internal/pkg: append user-facing name in messages

This makes verbose messages much more useful.

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

internal/pkg/pkg.go

@@ -8,6 +8,7 @@ import (
 	"encoding/base64"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io"
 	"io/fs"
 	"os"
@@ -278,6 +279,20 @@ func Ident(a Artifact) ID {
 	return a.Kind().Ident(a.Params(), a.Dependencies()...)
 }
 
+// reportNameIdent is like reportName but does not recompute [ID].
+func reportNameIdent(a Artifact, id ID) string {
+	r := Encode(id)
+	if s, ok := a.(fmt.Stringer); ok {
+		if name := s.String(); name != "" {
+			r += "-" + name
+		}
+	}
+	return r
+}
+
+// reportName returns a string describing [Artifact] presented to the user.
+func reportName(a Artifact) string { return reportNameIdent(a, Ident(a)) }
+
 // Kind corresponds to the concrete type of [Artifact] and is used to create
 // identifier for an [Artifact] with dependencies.
 type Kind uint64
@@ -725,6 +740,9 @@ func (c *Cache) openFile(f File) (r io.ReadCloser, err error) {
 		if !errors.Is(err, os.ErrNotExist) {
 			return
 		}
+		if c.msg.IsVerbose() {
+			c.msg.Verbosef("curing %s to memory...", reportName(f))
+		}
 		var data []byte
 		if data, err = f.Cure(c.ctx); err != nil {
 			return
@@ -917,7 +935,7 @@ func (c *Cache) Cure(a Artifact) (
 	}
 
 	if c.msg.IsVerbose() {
-		c.msg.Verbosef("curing %s...", Encode(id))
+		c.msg.Verbosef("curing %s...", reportNameIdent(a, id))
 	}
 
 	// cure File outside type switch to skip TContext initialisation