(BTW, does anyone know what's up with the darcsweb thingy for http://common-lisp.net/cgi-bin/darcsweb/darcsweb.cgi?r=postmodern-postmodern... ? It does seem to work for other projects, but postmodern breaks it... which is a shame.)
Never mind -- it was a weird Croatian letter that I accidentally added to a patch description while typing on a Croatian keyboard. I unrecorded it and replaced it by a patch with a regular ascii name, and everything works again.
Lesson: Darcsweb does not do unicode very well.
Cheers, Marijn