Michael, Today another Devuan report of this same issue was submitted[1]. Investigating further, the underlying cause appears to have been reported and fixed upstream[2].
As far as I can understand from the various Devuan, Artix and Gentoo reports, the failure is only evident on rsyslog builds without systemd using libc 2.42 which changed its modf() implementation and now requires explicit -lm linking. This explains you being unable to reproduce the issue on Debian. It would be a great help if you could cherry pick the upstream fix. Or I am happy to NMU if you would prefer? Thanks Mark [1] https://bugs.devuan.org/929 [2] https://github.com/rsyslog/libfastjson/pull/167
