python-venv-operator: termination log in alert

airflow/operators/python.py

@@ -400,6 +400,7 @@ def _execute_python_callable_in_subprocess(self, python_path: Path, tmp_dir: Pat
         output_path = tmp_dir / "script.out"
         string_args_path = tmp_dir / "string_args.txt"
         script_path = tmp_dir / "script.py"
+        termination_log_path = tmp_dir / "termination.log"
         self._write_args(input_path)
         self._write_string_args(string_args_path)
         write_python_script(
@@ -423,11 +424,17 @@ def _execute_python_callable_in_subprocess(self, python_path: Path, tmp_dir: Pat
                     os.fspath(input_path),
                     os.fspath(output_path),
                     os.fspath(string_args_path),
+                    os.fspath(termination_log_path),
                 ]
             )
         except subprocess.CalledProcessError as e:
             if e.returncode in self.skip_on_exit_code:
                 raise AirflowSkipException(f"Process exited with code {e.returncode}. Skipping.")
+            elif termination_log_path.exists() and termination_log_path.stat().st_size > 0:
+                error_msg = f"Process returned non-zero exit status {e.returncode}.\n"
+                with open(termination_log_path) as file:
+                    error_msg += file.read()
+                raise AirflowException(error_msg) from None
             else:
                 raise
 

airflow/utils/python_virtualenv_script.jinja2

@@ -49,7 +49,12 @@ with open(sys.argv[3], "r") as file:
 
 # Script
 {{ python_callable_source }}
-res = {{ python_callable }}(*arg_dict["args"], **arg_dict["kwargs"])
+try:
+    res = {{ python_callable }}(*arg_dict["args"], **arg_dict["kwargs"])
+except Exception as e:
+    with open(sys.argv[4], "w") as file:
+        file.write(str(e))
+    raise
 
 # Write output
 with open(sys.argv[2], "wb") as file:

tests/operators/test_python.py

@@ -681,6 +681,14 @@ def f():
         with pytest.raises(CalledProcessError):
             self.run_as_task(f)
 
+    def test_fail_with_message(self):
+        def f():
+            raise Exception("Custom error message")
+
+        with pytest.raises(AirflowException) as e:
+            self.run_as_task(f)
+            assert "Custom error message" in str(e)
+
     def test_string_args(self):
         def f():
             global virtualenv_string_args