"Unused const variable" build failure(s) — clang 3.9.1

With -Wall, clang detects useless const declaration:
static const int foo = 4;
and will fails with
$ clang -Werror -Wall -c foo.c 
foo.c:1:18: error: unused variable 'cbib_initial_size'
      [-Werror,-Wunused-const-variable]
static const int cbib_initial_size = 4;
                 ^
1 error generated.
PackageVersionSupposed error messageFull log Bug report
alljoyn-core-1504 15.04b-8alljoyn_core/router/UDPTransport.cc:449:16: error: unused variable 'UDP_WAIT_WATCHDOG_TIMEOUT' [-Werror,-Wunused-const-variable] Log
libgdf 0.1.2-2GDFHeaderAccess.cpp:28:14: error: unused variable 'epsilon_d' [-Werror,-Wunused-const-variable] Log 751540

2 errors