esp32: Using umqtt blocks access to webrepl

[Kriechi]

I'm using a ESP32-WROOM32 flashed with esp32-20181229-v1.9.4-762-gfa50047bb.bin.

When using umqtt in main.py with:

    c = MQTTClient('relay-board-esp32', 'example.com')
    c.set_callback(sub_cb)
    c.connect()
    c.subscribe('POWER')

    try:
        while True:
            c.wait_msg()
    finally:
        c.disconnect()

and webrepl in boot.py with:

import time
import network
import webrepl

nic = network.WLAN(network.STA_IF)
nic.active(True)
nic.connect('wifi', 'password')

while not nic.isconnected():
    time.sleep(1)

print('Connected to WiFi!')
print(nic.ifconfig())

webrepl.start()

no further connections via webrepl are possible.

Is this intended? Is there a solution or work around?
I thought the webrepl is listening in the background for new connections, but as soon as I run umqtt, webrepl does not accept new connections any more.

Does this mean no simultaneous access to webrepl and mqtt subscriptions is possible?

[dpgeorge]

Is this intended? Is there a solution or work around?
I thought the webrepl is listening in the background for new connections, but as soon as I run umqtt, webrepl does not accept new connections any more.

It's not intended but it is a consequence of how webrepl is implemented, how it "runs in the background". It basically polls the listening socket only under certain circumstances. As a work around you must call time.sleep_ms(12) for it to trigger a poll of the webrepl socket(s). Do that inside the while True loop that processes MQTT messages.

This should eventually be fixed, but it's not clear how to fix it efficiently.

(I thought there was an existing issue about this but couldn't find it.)