Thank you for taking the time to report this bug and helping to make Ubuntu better.
Looks like the check-mk source package embeds a copy of nagios' downtime.h (along with other header files), and that Nagios has updated a struct since then.
Patching Nagios doesn't make sense here, from a distribution perspective. The real fix is to fix check-mk's packaging to use a build dependency on some kind of nagios-dev package which provides the required headers. So this is a bug in check-mk, not in nagios.
This is probably relevant to Debian's check-mk packaging, too. Checking in Debian and reporting there if this bug applies to Debian would be appropriate.
Thank you for taking the time to report this bug and helping to make Ubuntu better.
Looks like the check-mk source package embeds a copy of nagios' downtime.h (along with other header files), and that Nagios has updated a struct since then.
Patching Nagios doesn't make sense here, from a distribution perspective. The real fix is to fix check-mk's packaging to use a build dependency on some kind of nagios-dev package which provides the required headers. So this is a bug in check-mk, not in nagios.
This is probably relevant to Debian's check-mk packaging, too. Checking in Debian and reporting there if this bug applies to Debian would be appropriate.