Vestiges of selfupdate still present

The backup prompt in the following log should not have happenned. FWIW, This is drush5 being executed outside of a Drupal site.

~/c/74$ drush dl drush --package-handler=git_drupalorg -v
Downloading release history from http://updates.drupal.org/release-history/drush/7.x                                                                    [notice]
http---updates.drupal.org-release-history-drush-7.x retrieved from cache.                                                                               [notice]
Downloading project drush to /tmp/drush_tmp_1319809216 ...                                                                                              [notice]
Executing: git clone --mirror --verbose --progress 'weitzman@git.drupal.org:project/drush.git' drush.git
Executing: git clone  --reference /Users/mweitzman/.drush/cache/git/drush.git --verbose --progress 'weitzman@git.drupal.org:project/drush.git' /tmp/drush_tmp_1319809216/drush
Executing: git tag -l 7.x-4.5
Executing: git checkout  7.x-4.5
Would you like to back up your current drush version 5.0-dev to /Users/mweitzman/drush-backups/unknown/20111028134015 and replace it with drush 4.5? (y/n): n
Executing: svn info /Users/mweitzman/c/74
Executing: bzr root /Users/mweitzman/c/74
Project drush (7.x-4.5) downloaded to /Users/mweitzman/c/74/drush.                                                                                   [success]
Command dispatch complete