I'm trying to upgrade a D5 site to D6 that uses send. I know send D6 is still only in alpha, but given that there are a bunch of send_update_N() functions already in send.install, I was thinking it might Just Work(tm). Alas... ;) Here's some output from drush updatedb -y once send 6.x-1.0-alpha4 is present in my site tree:

WD php: Undefined index:  mail in                                        [error]
/.../sites/all/modules/send/send.module on
line 103.
WD php: Undefined index:  mail in                                        [error]
/.../sites/all/modules/send/send.module on
line 107.
WD php: Undefined index:  mail in                                        [error]
/.../sites/all/modules/send/send.module on
line 116.
WD php: Table 'sw_6_www.send_contact' doesn't exist                      [error]
query: UPDATE send_contact_mail m
            INNER JOIN send_contact c USING ( scid )
            SET m.mail = '' WHERE c.uid = 1 in
/.../sites/all/modules/send/send.module on
line 116.
----
WD php: Duplicate entry 'xxxxxxx' for key 'mail'               [error]
query: INSERT INTO send_contact_mail (scid, name, mail)
    SELECT DISTINCT scid, name, mail FROM send_contact 
    WHERE mode = 'mail' AND mail IS NOT NULL in
/.../sites/all/modules/send/send.install on
line 535.
----
INSERT INTO {send_contact_mail} (scid, name, mail)                       [error]
    SELECT DISTINCT scid, name, mail FROM {send_contact} 
    WHERE mode = 'mail' AND mail IS NOT NULL
----
WD php: Undefined property: stdClass::$body in                           [error]
/.../sites/all/modules/send/send.install on
line 584.
WD php: Undefined property: stdClass::$body in                           [error]
/.../sites/all/modules/send/send.install on
line 584.
----
WD php: Undefined index:  send_node_type_blog_critical_reading in        [error]
/.../sites/all/modules/send/includes/send.api.inc
on line 144.
WD php: Undefined index:  send_node_type_story in                        [error]
/.../sites/all/modules/send/includes/send.api.inc
on line 144.
Table 'sw_6_www.send_contact' doesn't exist               [error]
query: UPDATE send_contact_mail m
            INNER JOIN send_contact c USING ( scid )
            SET m.mail = '' WHERE c.uid = 1 in
/.../sites/all/modules/send/send.module on
line 116.
Duplicate entry 'xxxxxxx' for key                    [error]
'mail'
query: INSERT INTO send_contact_mail (scid, name, mail)
    SELECT DISTINCT scid, name, mail FROM send_contact 
    WHERE mode = 'mail' AND mail IS NOT NULL in
/.../sites/all/modules/send/send.install on
line 535.

Haven't started debugging any of this yet, but wanted to at least open an issue about it. I searched and didn't see anything in the queue about problems during the upgrade path, so it's possible it's just something wonky about the D5 site I'm trying to upgrade. Anyway, I'll keep this issue updated with my findings, and if necessary, patches.

Cheers,
-Derek