drush cron fails: Drush command terminated abnormally due to an unrecoverable error $ drush -v -d cron
Bootstrap to phase 0. [0 sec, 1.65 MB]                               [bootstrap]
Drush bootstrap phase : _drush_bootstrap_drush() [0 sec, 1.77 MB]    [bootstrap]
Cache HIT cid: 5.4-commandfiles-0-33f01882e55343a61f1cb10880b0da0f [0.01 sec, 1.78 MB]                                          [debug]
Bootstrap to phase 0. [0.02 sec, 4.16 MB]                                                                                   [bootstrap]
Bootstrap to phase 6. [0.02 sec, 4.16 MB]                                                                                   [bootstrap]
Drush bootstrap phase : _drush_bootstrap_drupal_root() [0.02 sec, 4.17 MB]                                                  [bootstrap]
Initialized Drupal 7.28 root directory at ...htdocs [0.03 sec, 5.78 MB]                                [notice]
Drush bootstrap phase : _drush_bootstrap_drupal_site() [0.03 sec, 5.78 MB]                                                  [bootstrap]
Initialized Drupal site default at sites/default [0.03 sec, 5.79 MB]                                                           [notice]
Cache HIT cid: 5.4-commandfiles-2-c32acd775c18a90c5b41d0fc9accf5ab [0.03 sec, 5.79 MB]                                          [debug]
Drush bootstrap phase : _drush_bootstrap_drupal_configuration() [0.03 sec, 5.79 MB]                                         [bootstrap]
Drush bootstrap phase : _drush_bootstrap_drupal_database() [0.03 sec, 5.8 MB]                                               [bootstrap]
Successfully connected to the Drupal database. [0.03 sec, 5.8 MB]                                                           [bootstrap]
Drush bootstrap phase : _drush_bootstrap_drupal_full() [0.04 sec, 6.3 MB]                                                   [bootstrap]
Cache HIT cid: 5.4-commandfiles-5-21916586faf556c236c401ff89ea50f6 [0.18 sec, 33.52 MB]                                         [debug]
Drush bootstrap phase : _drush_bootstrap_drupal_login() [0.18 sec, 34.19 MB]                                                [bootstrap]
Successfully logged into Drupal as Anonymous (uid=0) [0.18 sec, 34.2 MB]                                                    [bootstrap]
Found command: core-cron (commandfile=core) [0.18 sec, 34.2 MB]                                                             [bootstrap]
Drush command terminated abnormally due to an unrecoverable error. [0.2 sec, 34.87 MB]                                      [error]


There's nothing showing up in admin/reports/dblog.

Note that heading to /cron.php?cron_key=... works fine from the web interface. But it fails when curling it from console.
(I also reported an issue at https://github.com/drush-ops/drush/issues/664 but was directed here.)

How can I find out what's wrong?

P.S. related: https://stackoverflow.com/questions/10014142/cron-fails-when-running-through-drush-and-calling-node-load
Apparently Elysia Cron was installed and in that case you have to 

drush elysia-cron


And drush cron is an alias of drush core-cron.