return "cannot find module providing package " + e.Path
		}

		if e.replaced.Path != "" {
			suggestArg := e.replaced.Path
			if !module.IsZeroPseudoVersion(e.replaced.Version) {
				suggestArg = e.replaced.String()
			}
			return fmt.Sprintf("module %s provides package %s and is replaced but not required; to add it:\n\tgo get %s", e.replaced.Path, e.Path, suggestArg)
		}