JuliusBrussee/caveman · error

file changed while opening

Error message

file changed while opening

What it means

Error "file changed while opening" thrown in JuliusBrussee/caveman.

Source

Thrown at engine/ccr/store_sqlite.go:285

	if info.Mode()&os.ModeSymlink != 0 || !info.Mode().IsRegular() {
		return fmt.Errorf("refusing non-regular file")
	}
	file, err := os.OpenFile(path, os.O_RDWR, 0)
	if errors.Is(err, os.ErrNotExist) && !create {
		// The sidecar vanished between Lstat and open — a concurrent process
		// checkpointed the WAL and removed it. Nothing left to secure.
		return nil
	}
	if err != nil {
		return err
	}
	defer file.Close()
	opened, err := file.Stat()
	if err != nil {
		return err
	}
	if !os.SameFile(info, opened) {
		return fmt.Errorf("file changed while opening")
	}
	return file.Chmod(0o600)
}

func configureStorageBudget(db *sql.DB, maxBytes int64) error {
	var pageSize int64
	if err := db.QueryRow(`PRAGMA page_size`).Scan(&pageSize); err != nil {
		return fmt.Errorf("read page size: %w", err)
	}
	if pageSize <= 0 {
		return errors.New("invalid sqlite page size")
	}
	maxPages := maxBytes / pageSize
	if maxPages < 16 {
		return fmt.Errorf("budget %d is below SQLite minimum %d", maxBytes, 16*pageSize)
	}
	var applied int64
	if err := db.QueryRow(fmt.Sprintf(`PRAGMA max_page_count=%d`, maxPages)).Scan(&applied); err != nil {

View on GitHub (pinned to 27d5a3981a)

Solutions

1. The file changed while opening; retry the operation.

When it happens

Trigger: Thrown at engine/ccr/store_sqlite.go:285 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of JuliusBrussee/caveman@27d5a3981a (2026-08-15). Data as JSON: /api/errors/022026338ea130da. Report an issue: GitHub.