Starting wpa_supplicant in background mode via shell doesn't work

[paulwoodsagility]

I want to start wpa_supplicant on the target system and leave it running in the background (so I throw its -B option).

When I use the ppadb shell() method to do that, wpa_supplicant either doesn't run or stops immediately (can't tell which). I have been able to launch hostapd in the background using this method, so it doesn't seem like the problem is totally with ppadb.

However, I can use subprocess.run() as a workaround. When I use subprocess.run() to run adb shell with a wpa_supplicant command line, wpa_supplicant runs and remains running on the target, in the background, as desired. So it doesn't seem to be purely an adb thing. That sort of leaves me wondering about ppadb as the culprit.

Has anyone else run into this sort of thing (i.e., not being able to launch a daemon on the target using the shell() method)?