coreybutler/nvm-windows · warning

failed to get source file info: %v

Error message

failed to get source file info: %v

What it means

After copying bytes, copyFile stats the source file to mirror its permissions. This error means os.Stat(src) failed at that point — the source vanished or became inaccessible between the copy (which succeeded through its open handle) and the stat call. It is a TOCTOU-style race, usually triggered by antivirus quarantine or a concurrent cleanup of the temp tree.

Source

Thrown at src/upgrade/upgrade.go:944

	defer sourceFile.Close()

	// Create the destination file
	destinationFile, err := os.Create(dst)
	if err != nil {
		return fmt.Errorf("failed to create destination file: %v", err)
	}
	defer destinationFile.Close()

	// Copy contents from the source file to the destination file
	_, err = io.Copy(destinationFile, sourceFile)
	if err != nil {
		return fmt.Errorf("failed to copy file: %v", err)
	}

	// Optionally, copy file permissions (this can be skipped if not needed)
	sourceInfo, err := os.Stat(src)
	if err != nil {
		return fmt.Errorf("failed to get source file info: %v", err)
	}

	err = os.Chmod(dst, sourceInfo.Mode())
	if err != nil {
		return fmt.Errorf("failed to set file permissions: %v", err)
	}

	return nil
}

// copyDirContents copies all the contents (files and subdirectories) of a source directory to a destination directory.
func copyDirContents(srcDir, dstDir string) error {
	// Ensure destination directory exists
	err := os.MkdirAll(dstDir, 0755)
	if err != nil {
		return fmt.Errorf("failed to create destination directory %s: %v", dstDir, err)
	}

View on GitHub (pinned to 5b18223ca1)

Solutions

1. Add antivirus exclusions for the nvm temp pattern and NVM_HOME, then retry.
2. Close temp-cleanup tools during the upgrade.
3. Stat once before the copy and reuse that FileInfo instead of re-statting (code-level fix).
4. Retry — if the file survived this time the stat succeeds.

Example fix

// before
_, err = io.Copy(destinationFile, sourceFile)
...
sourceInfo, err := os.Stat(src)

// after: capture the stat for free from the open handle
sourceInfo, err := sourceFile.Stat()
if err != nil {
    return fmt.Errorf("failed to get source file info: %v", err)
}

Treat as non-fatal: the copy already succeeded, so log the stat failure, keep default permissions on the destination, and continue the upgrade.

When it happens

Trigger: AV deleting the source file microseconds after io.Copy finishes; another process pruning the nvm-upgrade-* temp dir mid-upgrade; source on removable/network media disconnected mid-operation.

Common situations: Aggressive real-time scanners treating just-downloaded exes as threats; temp-cleaner utilities; very slow disks making the race window wide.

Related errors

• Error rolling back node v%s installation: %v.
• unscheduling error: %v
• Error computing checksum: %v
• failed to copy file: %v
• error accessing %s: %v

AI-assisted analysis of coreybutler/nvm-windows@5b18223ca1 (2026-08-15). Data as JSON: /api/errors/92d60c63e65c45f7. Report an issue: GitHub.