entry := mustNewEnvSet(ver, baseOpts)
			baseEnvs.Store(key, entry)
			return entry, nil
		})
	} else {
		if entry, ok := baseEnvsWithOption.Load(key); ok {
			return entry.(*EnvSet)
		}
		entry, _, _ = baseEnvsWithOptionSingleflight.Do(key, func() (interface{}, error) {
			entry := mustNewEnvSet(ver, baseOptsWithoutStrictCost)
			baseEnvsWithOption.Store(key, entry)