Again with systemd in the new GPS Pi / 2020-07-04

Again and again systemd annoys me. This time in the GPS Pi configured for timing.

Since I want it to work perfectly at start I added the systemd rules as suggested by A Raspberry Pi Stratum 1 NTP Server - Phil's Occasional Blog with /etc/systemd/system/ublox-init.service containing:

[Unit]
Description=u-blox initialisation
Before=gpsd.service
Before=ntp.service

[Service]
Type=oneshot
ExecStart=/usr/local/bin/gpsctl -q -a -B 115200 --configure_for_timing

[Install]
WantedBy=multi-user.target

After reboot ntp was running, but no data at all from the gps unit, and gpsctl was unable to revive it. The solution was to disable the above unit and ntpd, powerdown and restart the whole system and try again. After that doing the changes by hand and starting ntpd worked fine.

It's probably some sort of race condition, but any time I try to make a system with systemd do something reliably I run into things like this.