if err != nil {
		if errors.Is(err, errNoChange) {
			return nil
		}
		return err
	}

	index := MainModules.GetSingleIndexOrNil()
	dirty := index.modFileIsDirty(modFile)
	if dirty && cfg.BuildMod != "mod" {
		// If we're about to fail due to -mod=readonly,
		// prefer to report a dirty go.mod over a dirty go.sum
		return errGoModDirty
	}