I ran an apt upgrade on my box and now NSD won’t start. I checked syslog and the only entry I can find is this, repeating over and over:
Aug 26 23:21:11 mail kernel: [ 261.679178] init: nsd main process ended, respawning
Aug 26 23:21:11 mail nsd[2978]: ...stale pid file from process 2959
Aug 26 23:21:11 mail nsd[2978]: did not get start signal from main
Aug 26 23:21:11 mail kernel: [ 261.898028] init: nsd main process (2978) terminated with status 1
I have made no other changes to this box prior to or after the apt-get upgrade, except that I upgraded to the newest version of mailinabox (from 18.0b) after the upgrade broke nsd, to see if that would solve the issue (it did not).