Hit a problem with the SDR driver. Under WeeWX3.9.2 it work perfectly.
With WeeWX 4.0.0b14 I hit this problem.
ar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** self.console = loader_function(config_dict, self)
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** File "/home/weewx/bin/user/sdr.py", line 147, in loader
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** return SDRDriver(**config_dict[DRIVER_NAME])
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** File "/home/weewx/bin/user/sdr.py", line 2667, in __init__
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** self._mgr.startup(cmd, path, ld_library_path)
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** File "/home/weewx/bin/user/sdr.py", line 207, in startup
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** (cmd, e))
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL weewx.engine: **** WeeWxIOError: failed to start process 'rtl_433 -f 868M -s 1024k -M utc -F json -R 78': [Errno 13] Permission denied
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL __main__: Unable to load driver: failed to start process 'rtl_433 -f 868M -s 1024k -M utc -F json -R 78': [Errno 13] Permission denied
Mar 09 00:18:24 raspberrypi weewxd[8537]: weewx[8537] CRITICAL __main__: **** Exiting...
Raspbian Buster on a Pi4B with a standard install. If I revert to 3.9.3, the problem goes away.
Any ideas?