benbjohnson/litestream · error

s3: cannot load aws config for region lookup: %w

Error message

s3: cannot load aws config for region lookup: %w

What it means

findBucketRegion's config.LoadDefaultConfig (a minimal config with credentials but no region) failed. Same class as main config load failure: broken shared AWS files, bad profile, or unreachable metadata service for the configured credential chain.

Source

Thrown at s3/replica_client.go:631

// findBucketRegion looks up the AWS region for a bucket. Returns blank if non-S3.
func (c *ReplicaClient) findBucketRegion(ctx context.Context, bucket string) (string, error) {
	// Build a config with credentials but no region
	configOpts := []func(*config.LoadOptions) error{
		config.WithRetryer(newTransportRetryer),
	}

	// Add static credentials if provided
	if c.AccessKeyID != "" && c.SecretAccessKey != "" {
		configOpts = append(configOpts, config.WithCredentialsProvider(
			credentials.NewStaticCredentialsProvider(c.AccessKeyID, c.SecretAccessKey, ""),
		))
	}

	// Load AWS configuration
	cfg, err := config.LoadDefaultConfig(ctx, configOpts...)
	if err != nil {
		return "", fmt.Errorf("s3: cannot load aws config for region lookup: %w", err)
	}

	// Use default region for initial region lookup
	cfg.Region = DefaultRegion

	// Create S3 client options
	s3Opts := []func(*s3.Options){}

	// Configure custom endpoint for region lookup
	c.configureEndpoint(&s3Opts)

	client := s3.NewFromConfig(cfg, s3Opts...)

	// Get bucket location
	out, err := client.GetBucketLocation(ctx, &s3.GetBucketLocationInput{
		Bucket: aws.String(bucket),
	})
	if err != nil {

View on GitHub (pinned to 4ed7a308f6)

Solutions

1. Fix AWS shared config/credentials files
2. Set region explicitly to skip the region lookup entirely

When it happens

Trigger: Thrown at s3/replica_client.go:631 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of benbjohnson/litestream@4ed7a308f6 (2026-09-06). Data as JSON: /api/errors/1f8cc721a52c217a. Report an issue: GitHub.