# tmux.CommandError.Is

- **Module:** tmux.CommandError
- **Package:** github.com/libtmux/libtmux-go/tmux
- **Language:** Go
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-go/blob/52968a3181c1c9e6d1b26c565d4b170968ae61c0/tmux/command.go#L149
- **Page:** https://libtmux.org/en/go/latest/reference/tmux-commanderror-is/

```
tmux.CommandError.Is(target: error) -> bool
```

Is reports [ErrNoServer] for a failure that means no tmux server answered — either the command never reached one, or the one it reached is gone — and [ErrNotFound] for one tmux refused because the object it named was absent.