Zephyr has built-in debugging for many of its supported boards. Here's a real-world example of utilizing the these tools to track down and fix a networking error with CoAP.
Golioth communicates with IoT devices using the CoAP protocol. While our official SDK is built on Zephyr, any platform with CoAP and pre-shared key authentication can be used on the Golioth platform. Here's how to set up the ESP-IDF to work with Golioth.