failed to open original source file for conversion: %w

Error message

failed to open original source file for conversion: %w

What it means

After rewriting the copyright/SPDX comment lines in the parsed AST, conv opens the original source file with os.OpenFile(path, os.O_TRUNC|os.O_RDWR, 0660) to rewrite it in place. If the file cannot be opened — missing permissions, read-only filesystem, or the file vanished between parsing and opening — this wrapped error is returned.

Source

Thrown at tools/spdxconv/main.go:102

	}
	var spdx string
	for exp, tmp := range RegexpMap {
		if exp.MatchString(cg.Text()) {
			spdx = tmp
		}
	}
	if spdx == "" {
		log.Printf("could not determine license for %v", path)
		return nil
	}

	copyRight := cg.List[0].Text
	cg.List[0].Text, cg.List[1].Text = spdx, copyRight
	cg.List = cg.List[:2]

	fd, err := os.OpenFile(path, os.O_TRUNC|os.O_RDWR, 0660)
	if err != nil {
		return fmt.Errorf("failed to open original source file for conversion: %w", err)
	}
	defer fd.Close()

	err = format.Node(fd, fset, f)
	if err != nil {
		return fmt.Errorf("failed to write converted file %v: %w", path, err)
	}

	return nil
}

func main() {
	switch {
	case len(os.Args) != 2:
		fmt.Print(usage)
		os.Exit(1)
	case os.Args[1] == "help":
		fmt.Print(usage)

View on GitHub (pinned to ac7b90affa)

Solutions

Check and fix file permissions: chmod u+w <file> or run the tool as the file owner.
Ensure the filesystem/mount is writable (remount rw, drop the read-only flag in CI).
Verify the file still exists; re-run the tool on a clean checkout.

Example fix

// before
chmod 444 pkg/foo.go && spdxconv ./pkg
// after
chmod 644 pkg/foo.go && spdxconv ./pkg

Defensive patterns

Strategy: validation

Validate before calling

info, err := os.Stat(path)
if err != nil || !info.Mode().IsRegular() {
	return fmt.Errorf("%s not a writable regular file", path)
}
if f, err := os.OpenFile(path, os.O_WRONLY, 0); err != nil { return err } else { f.Close() }

Try / catch

if err := conv(path, fset, f); err != nil {
	if errors.Is(err, fs.ErrPermission) {
		// escalate or skip file
	}
	return err
}

Prevention

Run the tool as a user with write access to all target files.
Ensure the workspace mount is read-write (CI checkout, container volumes).
Stat paths before conversion to confirm they are regular writable files.

When it happens

Trigger: os.OpenFile fails on the target .go file: no write permission (non-root running against files owned by another user), the file was deleted after parsing, a device/permission mismatch, or O_TRUNC on a path that is not a regular file.

Common situations: Running spdxconv in CI as a non-privileged user against a checked-out tree with restricted permissions; read-only container mounts; converting files under /proc or similar pseudo-filesystems.

Related errors

AI-assisted analysis of cilium/cilium@ac7b90affa (2026-08-31). Data as JSON: /api/errors/5cf2d51c673708eb. Report an issue: GitHub.