[stable-2.9] package_facts - use AnsibleModule.warn() for warnings

(cherry picked from commit 2b1e24fc49)

Co-authored-by: Sam Doran <sdoran@redhat.com>

changelogs/fragments/package-facts-use-module-warnings.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - package_facts - use module warnings rather than a custom implementation for reporting warnings

lib/ansible/module_utils/facts/packages.py

@@ -18,8 +18,6 @@ def get_all_pkg_managers():
 
 class PkgMgr(with_metaclass(ABCMeta, object)):
 
-    warnings = []
-
     @abstractmethod
     def is_available(self):
         # This method is supposed to return True/False if the package manager is currently installed/usable

lib/ansible/modules/packaging/os/package_facts.py

@@ -230,7 +230,7 @@ class RPM(LibMgr):
         ''' we expect the python bindings installed, but this gives warning if they are missing and we have rpm cli'''
         we_have_lib = super(RPM, self).is_available()
         if not we_have_lib and get_bin_path('rpm'):
-            self.warnings.append('Found "rpm" but %s' % (missing_required_lib('rpm')))
+            module.warn('Found "rpm" but %s' % (missing_required_lib('rpm')))
         return we_have_lib
 
 
@@ -256,7 +256,7 @@ class APT(LibMgr):
         if not we_have_lib:
             for exe in ('apt', 'apt-get', 'aptitude'):
                 if get_bin_path(exe):
-                    self.warnings.append('Found "%s" but %s' % (exe, missing_required_lib('apt')))
+                    module.warn('Found "%s" but %s' % (exe, missing_required_lib('apt')))
                     break
         return we_have_lib
 
@@ -382,9 +382,6 @@ def main():
                     module.warn('Requested package manager %s was not usable by this module: %s' % (pkgmgr, to_text(e)))
                 continue
 
-            for warning in getattr(manager, 'warnings', []):
-                module.warn(warning)
-
         except Exception as e:
             if pkgmgr in module.params['manager']:
                 module.warn('Failed to retrieve packages with %s: %s' % (pkgmgr, to_text(e)))