internal/pkg: log fault in tests when available

This would otherwise only be available in verbose output, interleaved with everything else.

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

internal/pkg/pkg_test.go

@@ -21,6 +21,7 @@ import (
 	"syscall"
 	"testing"
 	"testing/fstest"
+	"time"
 	"unique"
 	"unsafe"
 
@@ -561,6 +562,21 @@ func cureMany(t *testing.T, c *pkg.Cache, steps []cureStep) {
 	for _, step := range steps {
 		t.Log("cure step:", step.name)
 		if pathname, checksum, err := c.Cure(step.a); !reflect.DeepEqual(err, step.err) {
+			faults, _err := c.ReadFaults(step.a)
+			if _err != nil {
+				t.Errorf("ReadFaults: error = %v", _err)
+			}
+
+			var p []byte
+			for _, fault := range faults {
+				p, _err = os.ReadFile(fault.String())
+				if _err != nil {
+					t.Error(_err)
+					continue
+				}
+				t.Log(string(p))
+				t.Logf("faulting cure terminated %s ago", time.Since(faults[0].Time()))
+			}
 			t.Fatalf("Cure: error = %v, want %v", err, step.err)
 		} else if step.pathname != ignorePathname && !pathname.Is(step.pathname) {
 			t.Fatalf("Cure: pathname = %q, want %q", pathname, step.pathname)