MOS CLI RPC via AWS MQTT Connect Error

#1

I want to call Config.Get via mos cli call command through AWS IoT MQTT.

I’m using:

mos --ca-cert-file ca.pem --cert-file aws-esp8266_B3F282.crt.pem --key-file aws-esp8266_B3F282.key.pem --port mqtt://a1ybm1dzxx22hk-ats.iot.us-west-2.amazonaws.com:8883/esp8266_B3F282 call Config.Get

In the same folder with the same .pem files and configuration my ESP8266 device is currently successfully connecting to AWS with. And I get this error:

E0504 17:38:47.445075   19420 reconnect_wrapper.go:103] [reconnectWrapperCodec to mqtt://a1ybm1dzxx22hk-ats.iot.us-west-2.amazonaws.com:8883/esp8266_B3F282; connect in 2.00s] connection error: MQTT connect error: Network Error : %!s(<nil>)
Network Error : %!s(<nil>)
/private/tmp/mos-20190504-6508-13kowbb/mos-tool-2034cc00c37fee33b300b1c5869b8eeff328fdfa/src/cesanta.com/common/go/mgrpc/codec/mqtt.go:115: MQTT connect error
/private/tmp/mos-20190504-6508-13kowbb/mos-tool-2034cc00c37fee33b300b1c5869b8eeff328fdfa/src/cesanta.com/common/go/mgrpc/mgrpc.go:239:
E0504 17:38:49.680795   19420 reconnect_wrapper.go:103] [reconnectWrapperCodec to mqtt://a1ybm1dzxx22hk-ats.iot.us-west-2.amazonaws.com:8883/esp8266_B3F282; connect in 2.00s] connection error: MQTT connect error: Network Error : %!s(<nil>)
Network Error : %!s(<nil>)
/private/tmp/mos-20190504-6508-13kowbb/mos-tool-2034cc00c37fee33b300b1c5869b8eeff328fdfa/src/cesanta.com/common/go/mgrpc/codec/mqtt.go:115: MQTT connect error
/private/tmp/mos-20190504-6508-13kowbb/mos-tool-2034cc00c37fee33b300b1c5869b8eeff328fdfa/src/cesanta.com/common/go/mgrpc/mgrpc.go:239:

What am I missing to have the mos cli rpc connect through AWS MQTT?

p.s. I am able to subscribe AWS IoT MQTT topic successfully using the mosquitto cli client and using the same files as above:

mosquitto_sub --cert aws-esp8266_B3F282.crt.pem --key aws-esp8266_B3F282.key.pem --cafile ca.pem -h a1ybm1dzxx22hk-ats.iot.us-west-2.amazonaws.com -p 8883 -t '#'