Nagios Support Forum

True, but one would think that the code in the source is there for a reason...

Could be a safety measure to prevent mis-labeled perfdata? I recompiled NSClient++ without that line and didn't see any major issues with CheckCounter.

Probably worth raising an issue on the github if it's disruptive:
https://github.com/mickem/nscp/issues

Does your output using the recompiled version have the none?

It did not include the "none". A more time-efficient solution might be a simple sed as part of the CLI execution:

EDIT: Actually don't use sed. This discards the exit code and makes your check useless.

This can be closed...