coap client example does not connect to coap://californium.eclipse.org (IDFGH-5485)

[tiborrr]

Environment

• Development Kit: ESP32-Ethernet-Kit V1.2
• Module or chip used: ESP32-WROVER-E
• IDF version (run git describe --tags to find it): 8e3e65a47b7d9b5dc4f52eb56660a748fda1884e - v4.4-dev-1849-g8e3e65a47
• Build System: idf.py
• Compiler version (run xtensa-esp32-elf-gcc --version to find it): xtensa-esp32-elf-gcc (crosstool-NG esp-2021r1) 8.4.0
• Operating System: Linux
• Using an IDE?: Yes vscode with espressif extension
• Power Supply: USB/PoE

Problem Description

DNS can be found but the response is not as displayed in the example.

Expected Behavior

as presented in the example:

I (2582) CoAP_client: DNS lookup succeeded. IP=104.196.15.150
Received:
************************************************************
CoAP RFC 7252                              Cf 2.0.0-SNAPSHOT
************************************************************
This server is using the Eclipse Californium (Cf) CoAP framework
published under EPL+EDL: http://www.eclipse.org/californium/

(c) 2014, 2015, 2016 Institute for Pervasive Computing, ETH Zurich and others
************************************************************
...

Actual Behavior

I (184085) CoAP_client: DNS lookup succeeded. IP=198.41.30.194
E (189095) CoAP_client: select timeout

Steps to reproduce

Flash coap client example

[mrdeep1]

The URL has changed as of 9th. December 2020. It should becoaps://californium.eclipseprojects.io . There is a PR waiting to be merged that updates the libcoap version - see #7106 which includes this change.