Compiled it on Debian Testing: "No calendar client was found"

I compiled and installed Maya successfully on Debian Testing according to the instructions in the HACKING text file.

I can run it, but when I try work with it the log is full of _LOG_LEVEL_FATAL messages like "CalendarModel.vala:149: No calendar client was found" or "CalendarModel.vala:171: No calendar was found, event not added".

Unsurprisingly, adding events doesn't work (nothing happens after I click "create event" or whatever the button is called in English). The requester window just closes.

What am I doing wrong?