Drush doesn't download module version specified as dependency

Question

My module has a dependency to specific version of Media module (7.x-2.0-alpha4) and I have specified that in my info file as documented in Writing module .info files (Drupal 7.x) documentation, just like this:

name = mymodule
description = MyModule description.
package = Media

dependencies[] = file_entity
dependencies[] = media (7.x-2.0-alpha4)
dependencies[] = media_internet
dependencies[] = views

When I try to enable my module with it's dependencies drush en -y mymodule, Drush downloads current stable version of media module (7.x-1.5) instead of the specified one and then enabling my module fails because of unmet dependency. I'm doing this on plain Drupal installation v7.34, DevDesktop stack v 2 RC build Mar 18 2015, Drush v7.0.0-alpha9 (from DevDesktop).

I have also tried to specify the version as (2.0-alpha4) and (2.x) - without success.

What am I doing wrong? Thanks for any hints!

Answer 1

The Drush download code actually pre-dates this feature; as you have observed, it is not supported.

I have posted a feature request in the Drush issue queue, here:

https://github.com/drush-ops/drush/issues/1285

Answer 2

As @greg_1_anderson says, this feature is not supported yet, so such a dependency has to be downloaded and enabled in two steps

drush dl media-7.x-2.0-alpha4
....
drush en mymodule

Just running drush en -y mymodule will fail on unmet dependency.