Don't assume %_smp_mflags only ever contains -jX, use -j%_smp_build_ncpus directly

When we added %_smp_mflags here, Petr Viktorin asked the question:
https://src.fedoraproject.org/rpms/python-rpm-macros/pull-request/154#comment-124613

> I couldn't find docs for %_smp_mflags.
> How much of a guarantee is there that it contains no other flags than -j?

My answer was:

> %_smp_mflags is documented in https://rpm-packaging-guide.github.io/
> and used in many other RPM macros in Fedora and upstream everywhere.
> There is no official guarantee that it will never contain anything else,
> but if it does, I assume multiple things would burn.
> I am willing to take that risk.

Turns out, the world did not burn, but packagers do set %_smp_mflags to -lX,
which does not work with compileall.

Fixes https://bugzilla.redhat.com/2179149

macros.pybytecompile

@@ -35,18 +35,18 @@ py2_byte_compile () {\
 py34_byte_compile () {\
     python_binary="%{__env_unset_source_date_epoch_if_not_clamp_mtime} PYTHONHASHSEED=0 %1"\
     bytecode_compilation_path="%2"\
-    PYTHONPATH="%{_rpmconfigdir}/redhat" $python_binary -s -B -m compileall2 %{?_smp_mflags} -o 0 -o 1 -s $RPM_BUILD_ROOT -p / --hardlink-dupes $bytecode_compilation_path \
+    PYTHONPATH="%{_rpmconfigdir}/redhat" $python_binary -s -B -m compileall2 %{?_smp_build_ncpus:-j%{_smp_build_ncpus}} -o 0 -o 1 -s $RPM_BUILD_ROOT -p / --hardlink-dupes $bytecode_compilation_path \
 }\
 py37_byte_compile () {\
     python_binary="%{__env_unset_source_date_epoch_if_not_clamp_mtime} PYTHONHASHSEED=0 %1"\
     bytecode_compilation_path="%2"\
-    PYTHONPATH="%{_rpmconfigdir}/redhat" $python_binary -s -B -m compileall2 %{?_smp_mflags} -o 0 -o 1 -s $RPM_BUILD_ROOT -p / --hardlink-dupes --invalidation-mode=timestamp $bytecode_compilation_path \
+    PYTHONPATH="%{_rpmconfigdir}/redhat" $python_binary -s -B -m compileall2 %{?_smp_build_ncpus:-j%{_smp_build_ncpus}} -o 0 -o 1 -s $RPM_BUILD_ROOT -p / --hardlink-dupes --invalidation-mode=timestamp $bytecode_compilation_path \
 }\
 \
 py39_byte_compile () {\
     python_binary="%{__env_unset_source_date_epoch_if_not_clamp_mtime} PYTHONHASHSEED=0 %1"\
     bytecode_compilation_path="%2"\
-    $python_binary -s -B -m compileall %{?_smp_mflags} -o 0 -o 1 -s $RPM_BUILD_ROOT -p / --hardlink-dupes --invalidation-mode=timestamp $bytecode_compilation_path \
+    $python_binary -s -B -m compileall %{?_smp_build_ncpus:-j%{_smp_build_ncpus}} -o 0 -o 1 -s $RPM_BUILD_ROOT -p / --hardlink-dupes --invalidation-mode=timestamp $bytecode_compilation_path \
 }\
 \
 # Path to intepreter should not contain any arguments \

macros.python-srpm

@@ -78,7 +78,7 @@
 %__env_unset_source_date_epoch_if_not_clamp_mtime %[0%{?clamp_mtime_to_source_date_epoch} == 0 ? "env -u SOURCE_DATE_EPOCH" : "env"]
 
 ## The individual BRP scripts
-%__brp_python_bytecompile %{__env_unset_source_date_epoch_if_not_clamp_mtime} %{_rpmconfigdir}/redhat/brp-python-bytecompile "" "%{?_python_bytecompile_errors_terminate_build}" "%{?_python_bytecompile_extra}" "%{?_smp_mflags}"
+%__brp_python_bytecompile %{__env_unset_source_date_epoch_if_not_clamp_mtime} %{_rpmconfigdir}/redhat/brp-python-bytecompile "" "%{?_python_bytecompile_errors_terminate_build}" "%{?_python_bytecompile_extra}" "%{?_smp_build_ncpus:-j%{_smp_build_ncpus}}"
 %__brp_fix_pyc_reproducibility %{_rpmconfigdir}/redhat/brp-fix-pyc-reproducibility
 %__brp_python_hardlink %{_rpmconfigdir}/redhat/brp-python-hardlink
 

python-rpm-macros.spec

@@ -53,7 +53,7 @@ elseif posix.stat('macros.python-srpm') then
 end
 }
 Version:        %{__default_python3_version}
-Release:        9%{?dist}
+Release:        10%{?dist}
 
 BuildArch:      noarch
 
@@ -163,6 +163,10 @@ grep -E '^#[^%%]*%%[^%%]' %{buildroot}%{rpmmacrodir}/macros.* && exit 1 || true
 
 
 %changelog
+* Thu Mar 16 2023 Miro Hrončok <mhroncok@redhat.com> - 3.11-10
+- Don't assume %%_smp_mflags only ever contains -jX, use -j%%_smp_build_ncpus directly
+- Fixes: rhbz#2179149
+
 * Fri Jan 20 2023 Miro Hrončok <mhroncok@redhat.com> - 3.11-9
 - Memoize values of macros that execute python to get their value
 - Fixes: rhbz#2155505