I'm trying to automate the use of the provision drush extension. Mostly that works well, but I can't make a custom drush extension perform a provision-install command, unless I manually use proc_open to call drush again directly.
To keep my code consistent, and use drush's API as much as possible, I would like to avoid any direct spawning of new processes.
So: what I want to work is the call I use for other drush commands, which is drush_backend_process('@sitealias', 'provision-install', array());"
1) Why does this work for other commands using @aliases, but not provision-install? 2) How well can I make it work, within drush's API? (So as to avoid direct use of proc_open)
More info in this issue: https://drupal.org/node/1844038