Empty character constant - Rebuild of the Debian archive with clang

"Empty character constant " build failure(s)
clang 3.1

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
elmerfem	6.1.0.svn.5396.dfsg-5.2	iso_varying_string.src:1363:14: error: empty character constant	Log
nut	2.6.4-1	./oneac.h:98:24: error: empty character constant	Log
vnc4	4.1.1+X4.3.0-37	./config/cf/Imake.rules:1627:27: error: empty character constant	Log
xcftools	1.0.7-4	./options.i:190:63: error: empty character constant	Log

4 errors

Debian Package rebuild