**SOLVED** (see below)

I'm trying to upgrade a Drupal site from 6.34 to 7.x using Drush.
When I run `drush site-upgrade @alias`, everything goes well until step 12-a where it ends up throwing this error :

    Unknown option: --uninstall.  See `drush help pm-disable` for available options. To suppress this error, add the option --strict=0.

I made some search about this and tried a few things :

- I created a file ~/.drush/my.drushrc.php using the example code given here : http://api.drush.org/api/drush/examples%21example.drushrc.php/6.x
I then uncommented line 198 :

`$options['strict'] = FALSE;`

- In that same drushrc file, I added this line :

`$command_specific['pm-disable'] = array('strict' => 0);`

This solution was proposed here : https://www.drupal.org/node/2074781

- I then tried defining a drush alias in my .bash_aliases (http://drupal.stackexchange.com/a/128974/39434)

`alias	drush='drush --strict=0'`

Neither of these solutions helped, I always get the same error.

    OS: Ubuntu 14.10
    Drush : 6.2.0
    PHP: 5.5.12-2ubuntu4.1 (cli)

----------

I actually solved the issue while asking the question but I figured I would post both the question and its solution in case somebody else has the same problem.

My Drush configuration file was simply misplaced, I had to put it in Drupal's directory (sites/all/drush/drushrc.php) rather than ~/.drush/

When running

    drush status

From your Drupal source site directory, make sure there is a Drush configuration loaded.

    Drush version                   :  6.2.0
    Drush configuration             :  /var/www/html/drupal/sites/all/drush/drushrc.php
    Drush alias files               :  /root/.drush/my.alias.drushrc.php


And here is the content of file sites/all/drush/drushrc.php

    <?php
    $options['strict'] = FALSE;