"Unused function" build failure(s) — clang 3.3

-Wall -Werror are including the option -Wunused-function. Without not the case with g++
namespace { 
   void dummy_for_semicolon_do_not_use();
}
PackageVersionSupposed error messageFull log Bug report
cdebootstrap 0.5.10../../../../src/frontend/standalone/message.c:79:12: error: unused function 'unused' [-Werror,-Wunused-function] Log 751630
diagnostics 0.3.3-9annotations.cpp:46:1: error: unused function 'dummy_for_semicolon_do_not_use' [-Werror,-Wunused-function] Log 751904

2 errors