failed to stat sieve storage path: nonsense path

I have a mail server with postfix and dovecot installed. Postfix is configured to use dovecot's lmtp service in order to apply some sieve scripts.

mailbox_transport = lmtp:unix:private/dovecot-lmtp

And this seems to work so far. But when my server receives a mail to the account ilka (the same with all other accounts), I get this misterious error in the mail.log:

dovecot: lmtp(ilka): Error: wFYTAsmc7lvCLgAAinrl1Q: sieve: file storage: Failed to stat sieve storage path: stat(/var/mail//ilka/sieve/scripts/) failed: Not a directory

In dovecot's conf.d/90-sieve.conf I actually statet

sieve = file:~/sieve;active=~/.dovecot.sieve

So how does dovecot come up with this weird (and invalid) file path including two slashes? I am sure, I must have done some kind of very stupid misconfiguration, but I don't know where...

Thank you for your help!

Regards, Ilka

OK, I am just stupid:

I mixed up a few tutorials and did not keep track of which config files I changed. In dovecot.conf I overwrote the sieve configuration with this nonsense:

plugin {
    sieve_before = /var/mail/sieve/spam-global.sieve
    sieve_dir    = /var/mail/%d/%n/sieve/scripts/
    sieve        = /var/mail/%d/%n/sieve/active-script.sieve
}

I commented it out, now my mail server works fine and I can start to write some sieve rules.

The actual configuration, of course, is in

/etc/dovecot/conf.d/90-sieve.conf

making the default configuration for the location of the users' sieve script files:

sieve = file:~/sieve;active=~/.dovecot.sieve

Maybe someone will find this useful to learn from my mistake in the future.

Regards,

Ilka