In [1] capacity for $SUBJECT was added to most of the batch scripts, but
clean.bat was not included. I propose to do so with the attached patch.
By the way, are pgbison.bat and pgflex.bat directly called anywhere?
[1]
https://www.postgresql.org/message-id/2b7a674b-5fb0-d264-75ef-ecc7a31e54f8@postgrespro.ru
Regards,
Juan José Santamaría Flecha