lionsoul2014/ip2region · error

failed to detect IP version from `%s`: %s

Error message

failed to detect IP version from `%s`: %s

What it means

Go CLI helper: xdb.VersionFromHeader rejected the header — the structure version is not 2.0/3.0 or the ipVersion field is unknown, so the IP family of the database cannot be auto-detected.

Source

Thrown at binding/golang/main.go:99

	defer handle.Close()

	// verify the xdb file
	// @Note: do NOT call it every time you create a searcher since this will slow down the search response.
	// @see the util.Verify function for details.
	err = xdb.Verify(handle)
	if err != nil {
		return nil, fmt.Errorf("xdb verify: %w", err)
	}

	// auto-detect the ip version from the xdb header
	header, err := xdb.LoadHeader(handle)
	if err != nil {
		return nil, fmt.Errorf("failed to load header from `%s`: %s", dbPath, err)
	}

	version, err := xdb.VersionFromHeader(header)
	if err != nil {
		return nil, fmt.Errorf("failed to detect IP version from `%s`: %s", dbPath, err)
	}

	switch cachePolicy {
	case "nil", "file":
		return xdb.NewWithFileOnly(version, dbPath)
	case "vectorIndex":
		vIndex, err := xdb.LoadVectorIndexFromFile(dbPath)
		if err != nil {
			return nil, fmt.Errorf("failed to load vector index from `%s`: %w", dbPath, err)
		}

		return xdb.NewWithVectorIndex(version, dbPath, vIndex)
	case "content":
		cBuff, err := xdb.LoadContentFromFile(dbPath)
		if err != nil {
			return nil, fmt.Errorf("failed to load content from '%s': %w", dbPath, err)
		}

View on GitHub (pinned to c1a1fc7d59)

Solutions

1. Use a valid xdb whose header carries a recognized structure and ip version
2. Regenerate the database with the current maker
3. Manually construct the searcher with an explicit version if the header is known-good but nonstandard

When it happens

Trigger: Thrown at binding/golang/main.go:99 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of lionsoul2014/ip2region@c1a1fc7d59 (2026-09-02). Data as JSON: /api/errors/30cb9f4a2dbecc7b. Report an issue: GitHub.