Omnibus & ruby-shadow chef_gem

I’m trying to install the ruby-shadow gem as a chef_gem under omnibus so that the users::sysadmins recipe can set users’ passwords.

However, it fails with the following error:

ERROR: Failed to build gem native extension.

gem_make.out: https://gist.github.com/2763242

mkmf.log: https://gist.github.com/2763245

Is this a bug in omnibus?

Wes