JetsonNano + nvidia_MQT​T_publish_​subscribe model: Build Error > Error executing command "touch -c ; warning: assignment from incompatible pointer type [-Wincompatible-pointer

Target Hardware: Jetson Nano (4GB + Jetpack 4.6.1)

Host PC: Window System

Matlab Versio: R2025b

Jetson Nano connected with Host using a cross over ethernet cable. Host is connected to Internet through Wi-Fi

Objective: Build the Model "nvidia_MQTT_publish_subscribe" to execute the Example Model for MQTT.

Issue: Build Failed

Error executing command "touch -c /home/beda/MATLAB_ws/R2025b/C/Users/Admin/Documents/MATLAB/Examples/R2025b/nvidia/PublishAndSubscribeToMessagesOnThingSpeakUsingMQTTBlocksExample/nvidia_MQTT_publish_subscribe_ert_rtw/*.*;make -f nvidia_MQTT_publish_subscribe.mk -j4 all MATLAB_WORKSPACE="/home/beda/MATLAB_ws/R2025b" LINUX_TARGET_LIBS_MACRO="-lpaho-mqtt3as -ljson-c" -C /home/beda/MATLAB_ws/R2025b/C/Users/Admin/Documents/MATLAB/Examples/R2025b/nvidia/PublishAndSubscribeToMessagesOnThingSpeakUsingMQTTBlocksExample/nvidia_MQTT_publish_subscribe_ert_rtw". Details:

STDERR: /home/beda/MATLAB_ws/R2025b/C/ProgramData/MATLAB/SupportPackages/R2025b/toolbox/realtime/targets/linux/src/MW_MQTT.c: In function ‘brokerConn_handler’:

/home/beda/MATLAB_ws/R2025b/C/ProgramData/MATLAB/SupportPackages/R2025b/toolbox/realtime/targets/linux/src/MW_MQTT.c:409:31: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]

ssl_opts.ssl_error_cb = MW_MQTT_onSSLError;

^

make: *** No rule to make target '-lpaho-mqtt3as', needed by '../nvidia_MQTT_publish_subscribe.elf'. Stop.

Answer 1

[Satyam]

Hi @Beda Prakash,

I tried building this model on my end although I didn't try deploying it on hardware, yet it was built succesfully. I would suggest you to go through this documentation https://www.mathworks.com/help/coder/nvidia/ug/publish-subscribe-mqtt-nvidia-jetson.html and see if all the steps are being followed correctly while building the model. In case that doesn't work you can try troubleshooting the issue by following these steps:

• Jetson Nano has libpaho-mqtt1.3 and libjson-c-dev installed.
• Jetson reachable over SSH (same network or crossover).

I hope it helps.