caddyserver/caddy · error

overwriting formatted file: %v

Error message

overwriting formatted file: %v

What it means

Error "overwriting formatted file: %v" thrown in caddyserver/caddy.

Source

Thrown at cmd/commandfuncs.go:717

		if err != nil {
			return caddy.ExitCodeFailedStartup,
				fmt.Errorf("reading stdin: %v", err)
		}
		fmt.Print(string(caddyfile.Format(input)))
		return caddy.ExitCodeSuccess, nil
	}

	input, err := os.ReadFile(configFile)
	if err != nil {
		return caddy.ExitCodeFailedStartup,
			fmt.Errorf("reading input file: %v", err)
	}

	output := caddyfile.Format(input)

	if fl.Bool("overwrite") {
		if err := os.WriteFile(configFile, output, 0o600); err != nil { //nolint:gosec // path traversal is not really a thing here, this is either "Caddyfile" or admin-controlled
			return caddy.ExitCodeFailedStartup, fmt.Errorf("overwriting formatted file: %v", err)
		}
		return caddy.ExitCodeSuccess, nil
	}

	if fl.Bool("diff") {
		diff := difflib.Diff(
			strings.Split(string(input), "\n"),
			strings.Split(string(output), "\n"))
		for _, d := range diff {
			switch d.Delta {
			case difflib.Common:
				fmt.Printf("  %s\n", d.Payload)
			case difflib.LeftOnly:
				fmt.Printf("- %s\n", d.Payload)
			case difflib.RightOnly:
				fmt.Printf("+ %s\n", d.Payload)
			}
		}

View on GitHub (pinned to 50e54ee279)

Solutions

1. Check write permissions on the file and its directory before using --overwrite.
2. Close any program holding the file open and retry.

When it happens

Trigger: Thrown at cmd/commandfuncs.go:717 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of caddyserver/caddy@50e54ee279 (2026-08-15). Data as JSON: /api/errors/205d666e6886854c. Report an issue: GitHub.