"{\"topic\": \"dummy_topic\", \"msg\": \"{\"fruit\":\"apple\",\"dish\":\"apple-pie\"}\"}"
^^
That is where the error is, this matches exactly with what I said, the quotes aren’t escaped properly. The following should be valid:
~S'{"topic": "dummy_topic","msg":"{\"fruit\":\"apple\",\"dish\":\"apple-pie\"}"}'
Alternatively, you have to double escape in the msg field:
"{\"topic\": \"dummy_topic\", \"msg\": \"{\\\"fruit\\\":\\\"apple\\\",\\\"dish\\\":\\\"apple-pie\\\"}\"}"
I prefer the sigil approach for readability.
