change format envvar to override

Author: SammyRamone

launch/launch/actions/execute_local.py

@@ -74,8 +74,6 @@
 from ..utilities.type_utils import normalize_typed_substitution
 from ..utilities.type_utils import perform_typed_substitution
 
-DEFAULT_OUTPUT_FORMAT = '[{this.process_description.final_name}] {line}'
-
 
 class ExecuteLocal(Action):
     """Action that begins executing a process on the local system and sets up event handlers."""
@@ -91,7 +89,7 @@ def __init__(
             'sigkill_timeout', default=5),
         emulate_tty: bool = False,
         output: SomeSubstitutionsType = 'log',
-        output_format: Text = DEFAULT_OUTPUT_FORMAT,
+        output_format: Text = '[{this.process_description.final_name}] {line}',
         cached_output: bool = False,
         log_cmd: bool = False,
         on_exit: Optional[Union[
@@ -175,6 +173,7 @@ def __init__(
         :param: output_format for logging each output line, supporting `str.format()`
             substitutions with the following keys in scope: `line` to reference the raw
             output line and `this` to reference this action instance.
+            Overridden externally by the OVERRIDE_LAUNCH_OUTPUT_FORMAT envvar value.
         :param: log_cmd if True, prints the final cmd before executing the
             process, which is useful for debugging when substitutions are
             involved.
@@ -202,13 +201,11 @@ def __init__(
         else:
             self.__output = tmp_output
 
-        # Check if an environment variable is set and use this as a default
+        self.__output_format = output_format
+        # Check if an environment variable is set and override anything given as argument
         self.__output_format = os.environ.get(
-            'LAUNCH_OUTPUT_FORMAT', output_format
+            'OVERRIDE_LAUNCH_OUTPUT_FORMAT', self.__output_format
         )
-        # Setting it locally in the launch file still overwrites the default
-        if output_format != DEFAULT_OUTPUT_FORMAT:
-            self.__output_format = output_format
 
         self.__log_cmd = log_cmd
         self.__cached_output = cached_output