"Argument unused caused failure" build failure(s) — clang 10.0.0

Unknown or unused arguments triggers errors with -Werror:
clang -Werror -ggdb3 foo.c
PackageVersionSupposed error messageFull log Bug report
acpica-unix 20200326-1clang: error: argument unused during compilation: '-pie' [-Werror,-Wunused-command-line-argument] Log
libpsm2 11.2.86-1clang: error: argument unused during compilation: '-specs=/usr/share/dpkg/no-pie-compile.specs' [-Werror,-Wunused-command-line-argument] Log
librdkafka 1.3.0-1clang: error: argument unused during compilation: '-specs=/usr/share/dpkg/no-pie-compile.specs' [-Werror,-Wunused-command-line-argument] Log
python-pyxattr 0.6.1-2clang: error: argument unused during compilation: '-specs=/usr/share/dpkg/no-pie-compile.specs' [-Werror,-Wunused-command-line-argument] Log
skiboot 6.5.2-1clang: error: argument unused during compilation: '-specs=/usr/share/dpkg/no-pie-compile.specs' [-Werror,-Wunused-command-line-argument] Log
sphde 1.4.0-2clang: error: argument unused during compilation: '-mhtm' [-Werror,-Wunused-command-line-argument] Log

6 errors