golang/go · error

ErrFormat

ErrFormat

Error message

zip: not a valid zip file

What it means

Error "zip: not a valid zip file" thrown in golang/go.

Source

Thrown at src/archive/zip/reader.go:29

	"fmt"
	"hash"
	"hash/crc32"
	"internal/godebug"
	"io"
	"io/fs"
	"os"
	"path"
	"path/filepath"
	"slices"
	"strings"
	"sync"
	"time"
)

var zipinsecurepath = godebug.New("zipinsecurepath")

var (
	ErrFormat       = errors.New("zip: not a valid zip file")
	ErrAlgorithm    = errors.New("zip: unsupported compression algorithm")
	ErrChecksum     = errors.New("zip: checksum error")
	ErrInsecurePath = errors.New("zip: insecure file path")
)

// A Reader serves content from a ZIP archive.
type Reader struct {
	r             io.ReaderAt
	File          []*File
	Comment       string
	decompressors map[uint16]Decompressor

	// Some JAR files are zip files with a prefix that is a bash script.
	// The baseOffset field is the start of the zip file proper.
	baseOffset int64

	// fileList is a list of files sorted by ename,
	// for use by the Open method.

View on GitHub (pinned to b6b368adc5)

When it happens

Trigger: Thrown at src/archive/zip/reader.go:29 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of golang/go@b6b368adc5 (2026-08-12). Data as JSON: /api/errors/10cb84a7f8f76a6e. Report an issue: GitHub.