fix console script entry point

In the course, clean up how execution errors are processed, i.e. use
exceptions rather than integer return codes to indicate errors.

Signed-off-by: Nils Philippsen <nils@redhat.com>

distgit_bugzilla_sync/script.py

@@ -401,6 +401,13 @@ def _is_retired(product, project):
         return True
 
 
+class ScriptExecError(RuntimeError):
+
+    def __init__(self, *args, **kwargs):
+        self.errorcode = kwargs.pop('errorcode', 1)
+        super().__init__(*args, **kwargs)
+
+
 class DistgitBugzillaSync:
 
     def notify_users(self, errors):
@@ -587,8 +594,20 @@ class DistgitBugzillaSync:
             return override_yaml.get('bugzilla_contact', {})
         return {}
 
-    def main(self):
+    @classmethod
-        """The entrypoint to the script."""
+    def main(cls):
+        """The entrypoint for running the script."""
+        dbs = cls()
+        try:
+            dbs.run()
+        except ScriptExecError as e:
+            print(str(e), file=sys.stderr)
+            sys.exit(e.errorcode)
+        else:
+            sys.exit(0)
+
+    def run(self):
+        """Run the script."""
         global envname, env, projects_dict
         times = {
             "start": time.time(),
@@ -604,8 +623,7 @@ class DistgitBugzillaSync:
             if self.args.env in self.config['environments']:
                 envname = self.args.env
             else:
-                print(f"Invalid environment specified: {self.args.env}")
+                raise ScriptExecError(f"Invalid environment specified: {self.args.env}")
-                return 1
 
         self.env = self.config['environments'][envname]
 
@@ -736,9 +754,6 @@ class DistgitBugzillaSync:
             delta = times["end"] - times["start"]
             print(f"  Ran on {delta:.2f} seconds -- ie: {delta/60:.2f} minutes")
 
-        return 0
-
 
 if __name__ == '__main__':
-    dbs = DistgitBugzillaSync()
+    DistgitBugzillaSync.main()
-    sys.exit(dbs.main())

setup.py

@@ -40,7 +40,7 @@ setup(
     tests_require=TESTS_REQUIRE,
     entry_points={
         'console_scripts': [
-            'distgit-bugzilla-sync = distgit_bugzilla_sync.script:main',
+            'distgit-bugzilla-sync = distgit_bugzilla_sync.script:DistgitBugzillaSync.main',
         ],
     },
 )