What causes "error getting terminal size: %w" in abiosoft/colima?

Run the command directly in an interactive terminal instead of piping

error getting terminal size: %w

Error message

error getting terminal size: %w

What it means

verboseWriter.updateTerm (util/terminal/output.go:151) queries the terminal size via term.GetSize(os.Stdout.Fd()), throttled to once per 2 seconds; the wrapped error is almost always ENOTTY because stdout is not a terminal. printScreen (output.go:121) propagates the error, so the verbose live-view renderer aborts instead of drawing. A width<=0 case is already defended separately (falls back to 80), so the error path is specifically the ioctl failure.

Source

Thrown at util/terminal/output.go:151

}

func (v *verboseWriter) clearScreen() {
	for i := 0; i < v.screenHeight; i++ {
		ClearLine()
	}
	v.screenHeight = 0
}

func (v *verboseWriter) updateTerm() error {
	// no need to refresh so quickly
	if time.Since(v.lastUpdate) < time.Second*2 {
		return nil
	}
	v.lastUpdate = time.Now().UTC()

	w, _, err := term.GetSize(int(os.Stdout.Fd()))
	if err != nil {
		return fmt.Errorf("error getting terminal size: %w", err)
	}
	// A width of zero would result in a division by zero panic when computing overflow
	// in printScreen. Therefore, set it to a safe - even though probably wrong - value.
	// We use <= 0 here because negative values are guaranteed to lead to unexpected
	// results, even if they don't cause panics.
	if w <= 0 {
		w = 80
	}
	v.termWidth = w

	return nil
}

func countDisplayLines(line string, termWidth int) int {
	if termWidth <= 0 {
		termWidth = 80
	}

View on GitHub (pinned to c3a5f9184d)

Solutions

Run the command directly in an interactive terminal instead of piping
When piping is required, allocate a pty: `script -q /dev/null colima start ... | tee log.txt`
Inspect colima's own logs instead of stdout (e.g. `colima start --verbose` writes to log files under ~/.colima / ~/Library/Logs/colima)
If you embed this writer in your own tool, treat the updateTerm error as non-fatal and keep a default width of 80

Example fix

// before
out := v.printScreen() // returns error when stdout is piped, screen never renders

// after
if err := v.printScreen(); err != nil {
    // non-tty stdout: fall back to plain printing, don't kill the writer
    v.termWidth = 80
}

Defensive patterns

Strategy: fallback

Validate before calling

// detect non-tty stdout before enabling the live verbose writer
func stdoutIsTTY() bool {
    return term.IsTerminal(int(os.Stdout.Fd()))
}

Try / catch

if err := v.printScreen(); err != nil {
    // treat terminal-size failure as cosmetic: fall back to width 80 and keep running
    v.termWidth = 80
}

Prevention

Check term.IsTerminal before installing a terminal-aware writer
Default width to 80 and log at debug level instead of failing
Wrap piped runs in `script -q /dev/null ...` to provide a pty
Send machine-readable output to a file or stderr, not piped stdout

When it happens

Trigger: Running colima with verbose/live output piped or redirected: `colima start --verbose | tee log.txt`, `colima start > out.log`, or colima invoked from CI/daemon contexts where stdout has no controlling terminal.

Common situations: Piping colima output for logging in scripts; running colima in CI jobs; capturing output with subprocess pipes; terminal multiplexers that detach the pty mid-run.

Related errors

AI-assisted analysis of abiosoft/colima@c3a5f9184d (2026-08-15). Data as JSON: /api/errors/220c0d234d502372. Report an issue: GitHub.