JanDeDobbeleer/oh-my-posh · warning

terminal width must be greater than zero

Error message

terminal width must be greater than zero

What it means

resolveTerminalWidth parses the COLUMNS environment variable (via the shell) into a terminal width. The shared terminalErr covers failures, and this specific error is joined onto it when the parsed value is zero or negative, since a non-positive width would break prompt rendering math. It means the width source supplied a nonsensical value.

Source

Thrown at src/runtime/terminal_unix.go:90

	}

	term.CmdFlags.TerminalWidth = int(width)
	log.Debugf("terminal width: %d", term.CmdFlags.TerminalWidth)

	return term.CmdFlags.TerminalWidth, err
}

func resolveTerminalWidth(width uint, terminalErr error, columns string) (uint, error) {
	if width != 0 {
		return width, terminalErr
	}

	columnWidth, err := strconv.Atoi(columns)
	if err != nil {
		return 0, errors.Join(terminalErr, err)
	}
	if columnWidth <= 0 {
		return 0, errors.Join(terminalErr, errors.New("terminal width must be greater than zero"))
	}

	return uint(columnWidth), nil
}

func (term *Terminal) Platform() string {
	const key = "environment_platform"
	if val, found := cache.Device.Get[string](key); found {
		return val
	}

	var platform string
	defer func() {
		cache.Device.Set(key, platform, cache.INFINITE)
	}()

	if wsl := term.Getenv("WSL_DISTRO_NAME"); len(wsl) != 0 {
		platform, _, _ = strings.Cut(wsl, "-")

View on GitHub (pinned to 0976794618)

Solutions

1. Check the COLUMNS value in the shell where the prompt renders: `echo $COLUMNS` — unset or fix it if 0/negative.
2. Remove any `export COLUMNS=...` from shell startup files that sets a bogus value.
3. Run the prompt in a real TTY so COLUMNS reflects actual terminal size.
4. Update oh-my-posh if you need different fallback behavior for missing/invalid COLUMNS.

Example fix

// before (shell rc)
export COLUMNS=0
// after: let oh-my-posh/tput detect width, or set a positive value
export COLUMNS=120

// validate before rendering
cols := os.Getenv("COLUMNS")
if n, err := strconv.Atoi(cols); err != nil || n <= 0 {
    cols = "80" // safe fallback
}

func validWidth(s string) bool {
    n, err := strconv.Atoi(s)
    return err == nil && n > 0
}

w, err := term.TerminalWidth()
if err != nil {
    w = 80 // default width fallback
}

When it happens

Trigger: TerminalWidth (or an anonymous helper wrapping it) read a COLUMNS value that parsed to <= 0, e.g. COLUMNS=0 or COLUMNS=-1, on unix systems.

Common situations: Non-interactive shells or CI environments exporting COLUMNS=0; badly configured shell startup scripts exporting COLUMNS; tmux/screen edge cases; running under a wrapper that fakes terminal size.

Related errors

• environment access is disabled: rendering from recorded data
• failed to get shell config path: %w
• failed to get home directory

AI-assisted analysis of JanDeDobbeleer/oh-my-posh@0976794618 (2026-08-31). Data as JSON: /api/errors/6cb03d40d7fcd0ad. Report an issue: GitHub.