Do not use the system copy with non-KGTK output.
@@ -81,6 +81,8 @@ class KgtkCat():
print("Opening the %d input files." % len(self.input_file_paths), file=self.error_file, flush=True)
use_system_copy: bool = not self.pure_python
+ if self.output_format is not None and self.output_format != KgtkWriter.OUTPUT_FORMAT_KGTK:
+ use_system_copy = False
initial_column_names: typing.Optional[typing.List[str]] = None
saw_stdin: bool = False
