pio debug command line : how to attach a running target?

Hi,
in the doc I can't see how to attach to a running target to debug a crash,

https://github.com/platformio/platformio-docs/blob/develop/core/userguide/cmd_debug.rst

I guess the load-mode shall be overridden to manual

```
pio debug --interface=gdb --load-mode=manual and???
```

thanks for the precision