Comment 3 for bug 1872178

I'm slowly but surely ramping up my test bed.
On a broken PPS device you'd get:
  ubuntu gpsd[2585]: gpsd:ERROR: KPPS:/dev/pps0 time_pps_setparams(mode=0x1001) failed: unknown error

That happens if e.g. a device announced PPS but since it didn't initialize the kernel driver (by not soldering the PPS signal to a ping for example in my case). You are clearly past that.

But with another of my devices I think I can recreate the error now:
  gpsd[2649]: gpsd:WARN: KPPS:/dev/ttyUSB1 kernel PPS unavailable, PPS accuracy will suffer

After reducing to just the device that seems to have PPS (as the others throw a lot of false-positives) I can reproduce this and later this week hopefully debug it.