/usr/share/quilt/compat/sendmail is useless. Why not just require an MTA and use /usr/sbin/sendmail directly? Or at _least_ have the script use /usr/sbin/sendmail if it exists, and give its existing error message if not.
I'd fixed this locally; an update broke it again. Please fix.
Sigh. I hate it when I fail to see bug reports. My apologies for the delay. This seems to be caused by an incorrect option to configure. Replaced --with-mta with --with-sendmail and it appears to correctly point to /usr/sbin/sendmail via symlink. Fixed in quilt-0.47-4.fc11 (also quilt-0.47-3.fc10)