%pyproject_buildrequires: Generate BuildRequires for this package

This package is already installed -- otherwise the macro would not even exist.

However, since python3-devel has started to Require pyproject-rpm-macros,
it is no longer possible to use `repoquery --whatrequires pyproject-rpm-macros`
to get a reliable list of packages that use the macros.

This was, all packages that use %pyproject_buildrequires will BuildRequire the macros explicitly.

(In the future, we could even include a stub version of %pyproject_buildrequires
in pyproject-srpm-macros (always installed in the buildroot),
that only echoes this package,
so packagers would not need to manually BuildRequire anything at all.)

Related: rhbz#1950291

macros.pyproject

@@ -125,6 +125,7 @@ fi
 %{-t:%{error:The -N and -t options are mutually exclusive}}
 }
 %{-e:%{expand:%global toxenv %(%{__python3} -s %{_rpmconfigdir}/redhat/pyproject_construct_toxenv.py %{?**})}}
+echo 'pyproject-rpm-macros'  # we already have this installed, but this way, it's repoqueryable
 echo 'python%{python3_pkgversion}-devel'
 echo 'python%{python3_pkgversion}dist(pip) >= 19'
 echo 'python%{python3_pkgversion}dist(packaging)'

pyproject-rpm-macros.spec

@@ -12,7 +12,7 @@ License:        MIT
 # In other cases, such as backports, increment the point
 # release.
 Version:        0
-Release:        54%{?dist}
+Release:        55%{?dist}
 
 # Macro files
 Source001:      macros.pyproject
@@ -126,6 +126,10 @@ export HOSTNAME="rpmbuild"  # to speedup tox in network-less mock, see rhbz#1856
 %license LICENSE
 
 %changelog
+* Mon Jan 24 2022 Miro Hrončok <mhroncok@redhat.com> - 0-55
+- %%pyproject_buildrequires: Generate BuildRequires for this package
+  This package is already installed, but this way, the resulting SRPM explicitly BuildRequires it
+
 * Wed Jan 19 2022 Karolina Surma <ksurma@redhat.com> - 0-54
 - Include compressed manpages to the package if flag '+auto' is provided to %%pyproject_save_files