clarify package facts errors and warnings (#56060)

* clarify package facts errors and warnings

  fixes #56056

changelogs/fragments/package_facts_clarify.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - clarify error messages for 'auto' and missing libs, add missing lib msg for rpm.

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

@@ -155,7 +155,7 @@ ansible_facts:
 '''
 
 from ansible.module_utils._text import to_native, to_text
-from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.basic import AnsibleModule, missing_required_lib
 from ansible.module_utils.common.process import get_bin_path
 from ansible.module_utils.facts.packages import LibMgr, CLIMgr, get_all_pkg_managers
 
@@ -174,6 +174,13 @@ class RPM(LibMgr):
                     epoch=package[self._lib.RPMTAG_EPOCH],
                     arch=package[self._lib.RPMTAG_ARCH],)
 
+    def is_available(self):
+        ''' 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')))
+        return we_have_lib
+
 
 class APT(LibMgr):
 
@@ -195,9 +202,9 @@ class APT(LibMgr):
         ''' we expect the python bindings installed, but if there is apt/apt-get give warning about missing bindings'''
         we_have_lib = super(APT, self).is_available()
         if not we_have_lib:
-            for exe in ('apt', 'apt-get'):
+            for exe in ('apt', 'apt-get', 'aptitude'):
                 if get_bin_path(exe):
-                    self.warnings.append('Found "%s" but python bindings are missing, so we cannot get package information.' % exe)
+                    self.warnings.append('Found "%s" but %s' % (exe, missing_required_lib('apt')))
                     break
         return we_have_lib
 
@@ -291,7 +298,11 @@ def main():
 
     unsupported = set(managers).difference(PKG_MANAGER_NAMES)
     if unsupported:
-        module.fail_json(msg='Unsupported package managers requested: %s' % (', '.join(unsupported)))
+        if 'auto' in module.params['manager']:
+            msg = 'Could not auto detect a usable package manager, check warnings for details.'
+        else:
+            msg = 'Unsupported package managers requested: %s' % (', '.join(unsupported))
+        module.fail_json(msg=msg)
 
     found = 0
     seen = set()