"Argument unused caused failure" build failure(s) — clang 3.3

Unknown or unused arguments triggers errors with -Werror:
clang -Werror -ggdb3 foo.c
PackageVersionSupposed error messageFull log Bug report
bin-prot 2.0.9-1clang: error: argument unused during compilation: '-fno-defer-pop' Log
doxymacs 1.8.0-6clang: error: argument unused during compilation: '-fexpensive-optimizations' Log
libosl 0.5.0-1clang: error: argument unused during compilation: '-funswitch-loops' Log
libwebsockets 1.2.2-1clang: error: argument unused during compilation: '-rdynamic' Log
lio-utils 3.1+git2.fd0b34fd-2clang: error: argument unused during compilation: '-shared' Log
spice-vdagent 0.14.0-1clang: error: argument unused during compilation: '-Wp,-D_FORTIFY_SOURCE=2' Log

6 errors