plandex-ai/plandex · error

failed to seek in temporary file: %w

Error message

failed to seek in temporary file: %w

What it means

After writing the archive, doUpgrade seeks the temp file back to byte 0 before decompression. If the Seek call fails, it returns 'failed to seek in temporary file: %w'. This is rare and indicates the temp file handle is no longer usable (closed, or on a filesystem that cannot seek).

Source

Thrown at app/cli/upgrade.go:125

	}
	defer resp.Body.Close()

	// Create a temporary file to save the downloaded archive
	tempFile, err := os.CreateTemp("", "*.tar.gz")
	if err != nil {
		return fmt.Errorf("failed to create temporary file: %w", err)
	}
	defer os.Remove(tempFile.Name()) // Clean up file afterwards

	// Copy the response body to the temporary file
	_, err = io.Copy(tempFile, resp.Body)
	if err != nil {
		return fmt.Errorf("failed to save the downloaded archive: %w", err)
	}

	_, err = tempFile.Seek(0, 0)
	if err != nil {
		return fmt.Errorf("failed to seek in temporary file: %w", err)
	}

	// Now, extract the binary from the tempFile
	gzr, err := gzip.NewReader(tempFile)
	if err != nil {
		return fmt.Errorf("failed to create gzip reader: %w", err)
	}
	defer gzr.Close()

	tarReader := tar.NewReader(gzr)
	for {
		header, err := tarReader.Next()
		if err == io.EOF {
			break // End of archive
		}
		if err != nil {
			return fmt.Errorf("failed to read tar header: %w", err)
		}

View on GitHub (pinned to e2d772072e)

Solutions

1. Point TMPDIR at a normal local filesystem (e.g. /tmp or $HOME/tmp).
2. Check available file descriptors (ulimit -n) if the system is under heavy load.
3. Retry the upgrade; this failure is usually environment-specific and transient.
4. Report if it persists — the file may be closed prematurely in a modified build.

if _, err := tempFile.Seek(0, io.SeekStart); err != nil {
	os.Remove(tempFile.Name())
	return fmt.Errorf("failed to seek in temporary file: %w", err) // or reopen the file fresh and retry
}

When it happens

Trigger: tempFile.Seek(0, 0) returns an error — typically only when the file descriptor is invalid/closed or the underlying filesystem does not support seeking (some FUSE/network mounts).

Common situations: Custom TMPDIR on a network/FUSE mount with partial seek support; exotic sandboxed environments restricting file operations; file descriptor exhaustion causing odd handle states.

Related errors

• error reading settings-v2.json: %v
• error reading convo dir: %v
• error reading convo file: %v
• error reading convo message: %v
• error creating convo message descriptions dir: %v

AI-assisted analysis of plandex-ai/plandex@e2d772072e (2026-09-05). Data as JSON: /api/errors/e3fb9cde7d1c9e93. Report an issue: GitHub.