Merge branch 'report_source_of_parse_errors' of ssh://github.com/mostynb/cli into mostynb-report_source_of_parse_errors

flag_timestamp.go

@@ -133,9 +133,9 @@ func (f *TimestampFlag) Apply(set *flag.FlagSet) error {
 		f.Destination.SetLayout(f.Layout)
 	}
 
-	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {
+	if val, source, found := flagFromEnvOrFile(f.EnvVars, f.FilePath); found {
 		if err := f.Value.Set(val); err != nil {
-			return fmt.Errorf("could not parse %q as timestamp value for flag %s: %s", val, f.Name, err)
+			return fmt.Errorf("could not parse %q as timestamp value from %s for flag %s: %s", val, source, f.Name, err)
 		}
 		f.HasBeenSet = true
 	}