Description of problem:

Looks like redhat-rpm-config should inject -fcf-protection=full
instead of -fcf-protection.

rpmdiff complains:

Detecting usr/lib64/python3.6/site-packages/ovirt_imageio/_internal/ioutil.cpython-36m-x86_64-linux-gnu.so with not-hardened warnings '
Hardened: ioutil.cpython-36m-x86_64-linux-gnu.so: WARN: The annobin plugin was built to run on a newer version of the compiler
Hardened: ioutil.cpython-36m-x86_64-linux-gnu.so: FAIL: cf-protection test because no protection enabled 
Hardened: Rerun annocheck with --verbose to see more information on the tests.
' on x86_64

But fc-protection was used when building this package:

Brew build log:
http://{host}/brewroot/work/tasks/5592/43785592/build.log

gcc -pthread -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DNDEBUG -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -D_GNU_SOURCE -fPIC -fwrapv -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fPIC -I/usr/include/python3.6m -c ovirt_imageio/_internal/ioutil.c -o build/temp.linux-x86_64-3.6/ovirt_imageio/_internal/ioutil.o

gcc -pthread -shared -Wl,-z,relro -Wl,-z,now -g -Wl,-z,relro -Wl,-z,now -g -Wl,-z,relro -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection build/temp.linux-x86_64-3.6/ovirt_imageio/_internal/ioutil.o -L/usr/lib64 -lpython3.6m -o build/lib.linux-x86_64-3.6/ovirt_imageio/_internal/ioutil.cpython-36m-x86_64-linux-gnu.so

According to
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html-single/developing_c_and_cpp_applications_in_rhel_8/index#hardening-checker-options_hardening-checker-basics

We should have:

    If available, the -fcf-protection=full option was used.

gcc(1) does not document the meaning of -fcf-proection without an argument.

       -fcf-protection=[full|branch|return|none|check]
           Enable code instrumentation of control-flow transfers to increase
           program security by checking that target addresses of control-flow
           transfer instructions (such as indirect function call, function
           return, indirect jump) are valid.  This prevents diverting the flow
           of control to an unexpected target.  This is intended to protect
           against such threats as Return-oriented Programming (ROP), and
           similarly call/jmp-oriented programming (COP/JOP).

           The value "branch" tells the compiler to implement checking of
           validity of control-flow transfer at the point of indirect branch
           instructions, i.e. call/jmp instructions.  The value "return"
           implements checking of validity at the point of returning from a
           function.  The value "full" is an alias for specifying both
           "branch" and "return". The value "none" turns off instrumentation.

           The value "check" is used for the final link with link-time
           optimization (LTO).  An error is issued if LTO object files are
           compiled with different -fcf-protection values.  The value "check"
           is ignored at the compile time.

           The macro "__CET__" is defined when -fcf-protection is used.  The
           first bit of "__CET__" is set to 1 for the value "branch" and the
           second bit of "__CET__" is set to 1 for the "return".

           You can also use the "nocf_check" attribute to identify which
           functions and calls should be skipped from instrumentation.

           Currently the x86 GNU/Linux target provides an implementation based
           on Intel Control-flow Enforcement Technology (CET) which works for
           i686 processor or newer.

I'm not sure about the issue, it may be an issue in rpmdiff,
the wrong version of annobin, or may be using -fcf-protection
instead of -fcf-protection=full. -fcf-proection without an
argument is not documented, so it should not be used, or gcc
should fix the docs.

Version-Release number of selected component (if applicable):
redhat-rpm-config-125-1.el8.noarch (Used in Brew)
redhat-rpm-config-128-1.el8.noarch (tested in RHEL 8.6)