.bash_profile を source してくるやり方を試してみたところ、gem が入らなくなりました。
==> default: Error: Could not find command 'bundle'
==> default: Error: /Stage[main]/Main/Exec[install gem]/returns: change from notrun to 0 failed: Could not find command 'bundle'
==> default: Info: Creating state file /var/lib/puppet/state/state.yaml