How to download the projects within a distribution using git, not just the distribution itself?
There's no direct way to perform this.

This is a sequence that may fit for a dev environment. It is based on --package-handler=wget and drush make. No submodules. Contrib is downloaded to sites/all.

cd /tmp
drush dl commons --variant=profile-only
drush make commons/drupal-org-core.make distro
mv commons distro/profiles
rm -rf distro/sites/all/
drush make --no-core --no-gitinfofile --working-copy distro/profiles/commons/drupal-org.make  distro/sites/all


I used sites/all because drush make wants a non-existent destination, so distro/profiles/commons is not an option. An alternative is to perform the last make in a tmp directory and copy over the profile directory afterwards.



As a side note, drupal.org profiles provide three packages to download: profile-only, core-profile-and-projects, profile-and-projects. See http://drupal.org/node/1867206 for reference.

drush dl provides an option to choose among these three tarballs: --variant=&lt;full,projects,profile-only&gt;. All three options are available for --package-handler=wget whereas for git_drupalorg the only valid option is profile-only, since it corresponds to a single git project.

That said, there's room to implement a more complex workflow to provide (drush dl commons --variant=full --package-handler=git_drupalorg) by using submodules.