Merge pull request #2575 from cta-observatory/fix-sysexit-0

Bugfix: don't intercept normal SystemExit(0) in Tool

docs/changes/2575.bugfix.rst

@@ -0,0 +1 @@
+Fix a redundant error message in ``Tool`` caused by normal ``SystemExit(0)``

src/ctapipe/core/tool.py

@@ -452,18 +452,20 @@ def run(self, argv=None, raises=False):
                 if raises:
                     raise
             except SystemExit as err:
-                if raises:
-                    raise  # do not re-intercept in tests
-                else:
-                    exit_status = err.code
-                    self.log.exception(
-                        "Caught SystemExit with exit code %s", exit_status
-                    )
-                    Provenance().finish_activity(
-                        activity_name=self.name,
-                        status="error",
-                        exit_code=exit_status,
-                    )
+                exit_status = err.code
+                # Do nothing if SystemExit was called with the exit code 0 (e.g. with -h option)
+                if exit_status != 0:
+                    if raises:
+                        raise  # do not re-intercept in tests
+                    else:
+                        self.log.exception(
+                            "Caught SystemExit with exit code %s", exit_status
+                        )
+                        Provenance().finish_activity(
+                            activity_name=self.name,
+                            status="error",
+                            exit_code=exit_status,
+                        )
             finally:
                 if not {"-h", "--help", "--help-all"}.intersection(self.argv):
                     self.write_provenance()