At work we are moving to getting our new sites set up in git and doing local development. So far I've created a drush make file along with an installation profile, and I have this scripted via puppet so that when a user does a fresh clone of a repository it will download all of the packages and run a basic site install. This works OK.
Now, my question is for when I need to use a new module for a site. For example, we build a new module for the site. I want the other developers to pull from git and have the new module automatically installed. Adding it to the drush make file will only cause it to be downloaded, and running 'drush si' will cause the site to be reinstalled, wiping out all of the data.
What's the best way to accomplish this?
I feel I haven't explain this properly. I'm looking for a way to automatically enable modules based on the makefile entries in drush. The idea is the user checks out a project, and then I'll have puppet run 'drush make' and 'drush si' if no settings.php file exists. What I need to figure out is for when the next time the user does a pull and we've added a new module, how to have that automatically enabled through some script. If I need to I'll write something to parse the makefile and run 'drush en' manually, but I'd like to find something that is pre-built to do this.