[Evolution] Maildir account broken by update?

[fabien <fabien amiot wanadoo fr>]

Dear all,

I'm running Evolution 3.12.9 in Debian (Jessie) to display emails from
an IMAP, POP and MailDir accounts. This is the last version in Jessie,
namely 3.12.9~git20141130.241663-1. 
Earlier today a bunch of packages got updated (without any problem,
apparently). 

However, when starting Evolution afterwards, the emails related to the
MailDir account could no longer be displayed. 

In my preferences/Account/Receiving email page, the directory is now set
to (None) instead of my MailDir folder, and setting it back doesn't
help : opening the page again shows it's back to (None). 

Making Evolution re-create a new folders.db didn't help.

Also, trying to create a new MailDir account yields the same problem
than the initial MailDir account. It seems impossible to set the
Directory to something else than (None)...

Any idea?

Best regards,
Fabien