Created attachment 148521 [details]
Partially revert ports r371241 as ALSA ports are already properly ifdef'd since 1.0.28 update. The only exception is alsa-plugins/files/alsa-plugins.patch which wouldn't work on OSS code before FreeBSD 8.0 i.e., on DragonFly before issue 2633 resolved.
A commit references this bug:
Date: Mon Oct 20 21:31:07 UTC 2014
New revision: 371304
audio/alsa-*: drop USES=alias
Jan says alias is no longer needed on alsa since verion 1.0.28.
Thanks. I didn't have to verify this myself so I just relied on your advice that this is the correct thing to do for DragonFly. I'll find out soon enough on the next package build. :)