No sentence logs

[tangoing . mill745]

I am trying to do something gauche:

I run gpsd on the Raspberry Pi. My gps device doesn't conveniently
speak serial, only i2c, but there's a workingish python library that
can read the raw data from the gps device. I'm hoping to use the
python library and forward the data to an udp socket, and have gpsd
collect it like this:

  # /usr/sbin/gpsd -n -N -D 2 udp://127.0.0.1:12947

When I do this, gpsd does print some lines about it initializing,
and then there is a couple of lines that seem to indicate it does see
the data coming in -- there's a line saying it detected a particular
NMEA dialect, and then one about not being able to use time from GLL
and RMC sentences until it gets a ZDA one.

But after that, nothing. The manpage says -D2 should cause incoming
sentences to be logged, so what is going on?

Thanks for your help, gpsexperts.

-- 
Ian