PHP Fatal error: Cannot redeclare class DrushMakeProject_Core in /home/chris/.drush/drush/commands/make/make.project.inc on lin

For documentation purposes for those googling this i thought i'd provide the solution to this. Since i googled my error and usually it'll come up with an issue queue.

This error happens because I (installed aegir and it) had installed drush and drush make as well on my ubuntu machine and i also had it installed on my ~/.drush/ folder as well.

The simple solution to this is the remove the drush in my home folder (~/.drush/drush) or the native debian one.

Since i didn't need aegir anymore i just removed drush and drush make:

sudo apt-get purge drush drush-make

If you decide to nix the debian install of drush. You'll have to just recreate the symlink:
ln -s ~/.drush/drush/drush /usr/bin/drush