Merge "Avoid duplicate module names in the error from ModuleForTests."

				allVariants = append(allVariants, ctx.ModuleSubDir(m))

			}

		})

		sort.Strings(allModuleNames)

		sort.Strings(allVariants)

		if len(allVariants) == 0 {

			panic(fmt.Errorf("failed to find module %q. All modules:\n  %s",

				name, strings.Join(allModuleNames, "\n  ")))

				name, strings.Join(SortedUniqueStrings(allModuleNames), "\n  ")))

		} else {

			panic(fmt.Errorf("failed to find module %q variant %q. All variants:\n  %s",

				name, variant, strings.Join(allVariants, "\n  ")))