Unused private field - Rebuild of the Debian archive with clang

"Unused private field" build failure(s)
clang 6.0

clang -Wall -Werror will fail because bar is private (by default) and never used. g++ does not complain here.

class foo
{
    int bar;
};

Versions: 2.9 - 3.0 - 3.1 - 3.2 - 3.3 - 3.4 - 3.4.2 - 3.5.0 - 3.6.0 - 3.8.1 - 3.9.1 - 4.0.1 - 5.0 - 6.0 - 8.0.1 - 9.0.1 - 10.0.0 - 11.0.0 - 12.0.1 - 13.0.0

Package	Version	Supposed error message	Full log
drbd-utils	8.9.10-2	./CompactDisplay.h:159:19: error: private field 'out' is not used [-Werror,-Wunused-private-field]	Log
openni2	2.2.0.33+dfsg-10	DDK/XnPixelStream.h:135:9: error: private field 'm_bAllowCustomResolutions' is not used [-Werror,-Wunused-private-field]	Log
openzwave	1.5+ds-5	ValueList.h:85:11: error: private field 'm_newValueIdx' is not used [-Werror,-Wunused-private-field]	Log

3 errors

Debian Package rebuild