Can you retry with 1.0.12? It should be simple to update just the version and add any patches from current git just for the uClibc-ng package in buildroot. I remember some updates regarding lost messages...
I run a new test with the 1.0.12 version. It seems to fix the problem. Last stable version of buildroot seems to use 1.0.9. I will retry with this version.
Is it easy to find the bug which involves syslog between 1.0.5 & 1.0.12 ? I guess that I can use git log on syslog dictectory to find all fixes.
Because the best solution for me to validate the fix will be to backport the fix on 1.0.5 version and make a new test.
What syslog server are you using?
syslogd from busybox
Could you provide a complete sample application which reproduces the failure with 1.0.12?
Unfortunately I cannot share the code :(.
Arthur.