I have traced this down to the failing line
"if $upsmon -K >/dev/null 2>&1 ; then"
in /etc/init.d/ups-monitor -> nut-client
for some reason /sbin/upsmon after
open("/lib/i386-linux-gnu/i686/cmov/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
wants to read
open("/usr/lib/i386-linux-gnu/libnss3.so", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/i386-linux-gnu/libssl3.so", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/i386-linux-gnu/libplds4.so", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/i386-linux-gnu/libplc4.so", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/i386-linux-gnu/libnspr4.so", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/i386-linux-gnu/libnssutil3.so", O_RDONLY|O_CLOEXEC) = 3
none of which is available after /etc/rc0.d/K09umountfs called, I guess
