docs: def set_libs_flags(self, env, arch):
          '''Takes care to properly link libraries with python depending on our
          requirements and the attribute :attr:`opt_depends`.
          '''
          def add_flags(include_flags, link_dirs, link_libs):
              env['CPPFLAGS'] = env.get('CPPFLAGS', '') + include_flags
              env['LDFLAGS'] = env.get('LDFLAGS', '') + link_dirs
              env['LIBS'] = env.get('LIBS', '') + link_libs
  
          if 'sqlite3' in self.ctx.recipe_build_order:
              info('Activating flags for sqlite3')
              recipe = Recipe.get_recipe('sqlite3', self.ctx)
              add_flags(' -I' + recipe.get_build_dir(arch.arch),
                        ' -L' + recipe.get_lib_dir(arch), ' -lsqlite3')
  
          if 'libffi' in self.ctx.recipe_build_order:
              info('Activating flags for libffi')
              recipe = Recipe.get_recipe('libffi', self.ctx)
              # In order to force the correct linkage for our libffi library, we
              # set the following variable to point where is our libffi.pc file,
              # because the python build system uses pkg-config to configure it.
              env['PKG_CONFIG_PATH'] = recipe.get_build_dir(arch.arch)
              add_flags(' -I' + ' -I'.join(recipe.get_include_dirs(arch)),
                        ' -L' + join(recipe.get_build_dir(arch.arch), '.libs'),
                        ' -lffi')
  
          if 'openssl' in self.ctx.recipe_build_order:
              info('Activating flags for openssl')
              recipe = Recipe.get_recipe('openssl', self.ctx)
              add_flags(recipe.include_flags(arch),
                        recipe.link_dirs_flags(arch), recipe.link_libs_flags())
          return env