Each package may have a different set of repositories enabled and disabled. If we had these three packages:

    package { 'foo':
      enablerepo =>' repo1',
    }
    package { 'bar':
      enablerepo =>' repo1',
    }
    package { 'baz':
      enablerepo =>' repo1',
      disablerepo => 'repo2',
    }

Then repo_permutations would be

    [ { enablerepo: ['repo1'], disablerepo: [] }, { enablerepo: ['repo1'], disablerepo: ['repo2'] } ]