'not a tty' showing up after upgrade

I've seen this too, recently; I suspect it is coming from Drush backend invoke. I believe I have seen it in contexts other than site-upgrade, but I'll hold off on moving this to the Drush queue until better isolationed.

I tried to reproduce this a bit, but could not. I had a couple of these files on my disk, though, including inside projects that had never been used with the site-upgrade command. Most of these contained Drush log messages, like so:

Project libraries (7.x-2.0) downloaded to                            [success]
/path/to/drupal/sites/all/modules/libraries.

One had the output of the bash help command, though! One was created in May 2011. Moving to the Drush queue for wider consideration; even though I have not isolated the cause yet, I am pretty sure this is somewhere in Drush core.

Setting status, as we can't really do anything further here without better isolation.

This issue was marked closed (won't fix) because Drush has moved to Github.

If desired, you may copy this bug to our Github project and then post a link here to the new issue. Please also change the status of this issue to closed (duplicate).

Please ask support questions on Drupal Answers.