sql-dump imports old target dump file

When using an alias file dumping from a remote database to a local one, if %dump path is specified, drush fails to overwrite an existing dump file and imports the old file, from the first good dump. All subsequent imports will import that first dump.

Happens across sites.

If you change the name of the dump file in the alias file, drush imports the correct dump. That means it's not a permissions issue.

I found a temporary workaround by hacking the module.

Remove the if statement from sync.sql.inc on line 185 so that this

      if ($source_settings['dump-is-temp']) {
        $source_rsync_options['remove-source-files'] = TRUE;
      }

becomes this:

      $source_rsync_options['remove-source-files'] = TRUE;

Don't like that but it does the job. I can't find a cli switch for this option. Hoping somebody smarter than me will fix it!