drush up fails to update, though it says it deos Here's my output...

# drush up drupal-7.39
Failed to get available update data for one project.                                                                                                                [error]
Update information last refreshed: Wed, 09/16/2015 - 14:21

Update status information on all installed and enabled Drupal projects:
 Name         Installed version  Proposed version  Status
 Drupal core  7.38               7.39              Specified version available


Code updates will be made to drupal core.
WARNING:  Updating core will discard any modifications made to Drupal core files, most noteworthy among these are .htaccess and robots.txt.  If you have made any modifications to these files, please back them up before updating so that you can re-create your modifications in the updated version of the file.
Note: Updating core can potentially break your site. It is NOT recommended to update production sites without prior testing.

Do you really want to continue? (y/n): y
Project drupal was updated successfully. Installed version is now 7.39.
Backups were saved into the directory /root/drush-backups/civi2crm/20150916182131/drupal.                                                                           [ok]
Backups were restored successfully.                                                                                                                                 [ok]


And then if I immediately try the same thing again, I see that it still doesn't think it install 7.39.   I can confirm that /user#overlay=admin/reports/updates tells me that I am still running 7.38

# drush up drupal-7.39 -y
Failed to get available update data for one project.                                                                                                                [error]
Update information last refreshed: Wed, 09/16/2015 - 14:21

Update status information on all installed and enabled Drupal projects:
 Name         Installed version  Proposed version  Status
 Drupal core  7.38               7.39              Specified version available


Code updates will be made to drupal core.
WARNING:  Updating core will discard any modifications made to Drupal core files, most noteworthy among these are .htaccess and robots.txt.  If you have made any modifications to these files, please back them up before updating so that you can re-create your modifications in the updated version of the file.
Note: Updating core can potentially break your site. It is NOT recommended to update production sites without prior testing.

Do you really want to continue? (y/n): y
Project drupal was updated successfully. Installed version is now 7.39.
Backups were saved into the directory /root/drush-backups/civi2crm/20150916182138/drupal.                                                                           [ok]
Backups were restored successfully.


Any thoughts why I can't update Drupal.  And, in case it matters, I'm using Drupal to run CiviCRM.   And I think that is the "project" that it failed to get update data for.  But I believe I have to manually update CiviCRM by copying files and stuff, so that seems okay to me.   But perhaps I'm wrong on that.  But I can't see why, since I JUST want to patch the Drupal Core with the security update.
"Backups were restored successfully" means that Drush failed at some step, and restored your old version of Drupal over the recently updated version.  Try setting file ownership &amp;/or permissions; run with --debug, and perhaps you will see more information about why the upgrade is failing.