"Unused const variable" build failure(s) — clang 3.4.2

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
geis 2.2.16-1geis_backend_multiplexor.c:34:24: error: unused variable 'cbib_initial_size' [-Werror,-Wunused-const-variable] Log 751539
guile-cairo 1.4.0-3guile-cairo.c:204:1: error: unused variable 's_scm_cairo_version' [-Werror,-Wunused-const-variable] Log
guile-gnome-platform 2.16.2-1.1Foo-common.c:11:34: error: unused variable 'ORBit_zero_int' [-Werror,-Wunused-const-variable] Log
libgdf 0.1.2-2GDFHeaderAccess.cpp:28:14: error: unused variable 'epsilon_d' [-Werror,-Wunused-const-variable] Log 751540
ncap 1.9.2-1ncap_create.c:7:19: error: unused variable 'rcsid' [-Werror,-Wunused-const-variable] Log
xneur 0.15.0-1.1utils.c:46:18: error: unused variable 'total_mod_keys' [-Werror,-Wunused-const-variable] Log 751542

6 errors