[BRLTTY] Spurious logs on upgrade

[Samuel Thibault]

Hello,

A non-blind Debian user got a brltty upgrade, and /var/log got filled
up with errors.  What probably happened is that the old 4.4 daemon
was still running, but not finding any device. When the upgrade was
done to 4.5, the daemon was not restarted (that is on purpose to avoid
disrupting braille), but then the 4.4 daemon could not load its drivers
any more. The failing loop then became way shorter:

Jun 23 07:37:14 sanctuary brltty[1256]: /lib/brltty/libbrlttybal.so: undefined symbol: getMonotonicTime
Jun 23 07:37:14 sanctuary brltty[1256]: cannot load braille driver: /lib/brltty/libbrlttybal.so
Jun 23 07:37:14 sanctuary brltty[1256]: braille driver not loadable: al
Jun 23 07:37:14 sanctuary brltty[1256]: bm braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:14 sanctuary brltty[1256]: eu braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:14 sanctuary brltty[1256]: /lib/brltty/libbrlttybfs.so: undefined symbol: startTimePeriod
Jun 23 07:37:14 sanctuary brltty[1256]: cannot load braille driver: /lib/brltty/libbrlttybfs.so
Jun 23 07:37:14 sanctuary brltty[1256]: braille driver not loadable: fs
Jun 23 07:37:14 sanctuary brltty[1256]: /lib/brltty/libbrlttybht.so: undefined symbol: startTimePeriod
Jun 23 07:37:14 sanctuary brltty[1256]: cannot load braille driver: /lib/brltty/libbrlttybht.so
Jun 23 07:37:14 sanctuary brltty[1256]: braille driver not loadable: ht
Jun 23 07:37:14 sanctuary brltty[1256]: hm braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:14 sanctuary brltty[1256]: mt braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:14 sanctuary brltty[1256]: pg braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:14 sanctuary brltty[1256]: pm braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:14 sanctuary brltty[1256]: sk braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:14 sanctuary brltty[1256]: vo braille driver version 4.5 at 5477 does not match expected version 4.4 at 5477
Jun 23 07:37:19 sanctuary brltty[1256]: /lib/brltty/libbrlttybal.so: undefined symbol: getMonotonicTime
Jun 23 07:37:19 sanctuary brltty[1256]: cannot load braille driver: /lib/brltty/libbrlttybal.so
again, etc.

and eventually filled up /var/log.  Although the user just removed
brltty from his system, it would probably be a good idea to make the
failing loop longer, just like the the loop while no device is found?

Samuel