cannot run gpsd and zigbee2mqtt on the same RaspberryPi

[ProTofik]

Hi,

I am successfully running Zigbee2Mqtt on a Raspberry Pi4 with Slae.sh CC2652R zigbee stick for over 3 years now. I am running Ubuntu Server 22.04.

Today I wanted to turn the Pi into a Stratum 1 NTP Server using this guide. I've done it by connecting the module using the GPIO pins. I was successful, and it worked as expected.

The problem is that it appears Zigbee2Mqtt is crashing and failed to restart when the gpsd service is enabled. I get the following error in the logs:

[2024-08-24 19:52:23] info: z2m: Logging to console, file (filename: log.log)
[2024-08-24 19:52:23] info: z2m: Starting Zigbee2MQTT version 1.39.1 (commit #e132316)
[2024-08-24 19:52:23] info: z2m: Starting zigbee-herdsman (0.55.3)
[2024-08-24 19:52:26] info: zh:zstack:znp: Opening SerialPort with {"path":"/dev/serial/by-id/usb-Silicon_Labs_slae.sh_cc2652rb_stick_-slaesh_s_iot_stuff_00_12_4B_00_22_98_85_29-if00-port0","baudRate":115200,"rtscts":false,"autoOpen":false}
[2024-08-24 19:52:26] error: z2m: Error while starting zigbee-herdsman
[2024-08-24 19:52:26] error: z2m: Failed to start zigbee
[2024-08-24 19:52:26] error: z2m: Check https://www.zigbee2mqtt.io/guide/installation/20_zigbee2mqtt-fails-to-start.html for possible solutions
[2024-08-24 19:52:26] error: z2m: Exiting...
[2024-08-24 19:52:26] error: z2m: Error: Error: Device or resource busy, cannot open /dev/serial/by-id/usb-Silicon_Labs_slae.sh_cc2652rb_stick-_slaesh_s_iot_stuff_00_12_4B_00_22_98_85_29-if00-port0

The shae.sh stick is connected and discoverable:

root@home01net01pi:/# ls -l /dev/serial/by-id/
total 0
lrwxrwxrwx 1 root root 13 Nov 21 2023 usb-Silicon_Labs_slae.sh_cc2652rb_stick_-_slaesh_s_iot_stuff_00_12_4B_00_22_98_85_29-if00-port0 -> ../../ttyUSB0

So what is the problem, why Zigbee2Mqtt fails to connect to a USB device when gpsd service is running, even when the GPS module itself is physically disconnected? Where do I go next to troubleshoot this issue?