to whom it may concern:
Any penuin who hit the message
Failed to connect to wpa_supplicant - wpa_ctrl_open: No such file or directory
and after dogpiling your dog came back with this
or something else.
Unfortunately, (at least for me), this is NOT a bug. Nobody's fault, but me. It is crystal clear.
DO NOT TRY TO INVOKE **NON EXISTING INTERFACE**
I way trying to check several interfaces, I replaced interface with some other one, udev was so kind that wlan0 and wlan1 both exist. Then I tried to
where actual interface for wlan0 does not exist. That's how I got the error. I was sure that because only one interface exists, it was wlan0. I should have invoked wlan1, not wlan0.
Take home message:
Don't be silly as I am.
Debian testing, but I don't think it matters.