I should have been more clear in my comment. Seeing ports failing to build is not really enough.
There is still a fairly nasty limitation in our make wrt matching paths between targets that don't have the same filename, but are the same in the filesystem. This limitation prevents some ports to build in parallel, where make is the culprit that must be fixed (autoconf, for instance). There are also various race conditions in some ports proper, which actually prevent parallel building. Those are very different issues. Just asserting a port doesn't build in parallel is not enough to take proper action. If you can figure out what's going on, and make sure the port itself is broken (say, by checking that gmake exhibits the same broken behavior), then fixing the port/talking with upstream/marking as NO_PARALLEL is okay. It involves rather specific skills. As for that limitation, strategically, we would want to get rid of it eventually (it "just" involves me totally rewriting a large part of the core of make) rather than give in and use gpl code for building. But marking code as NO_PARALLEL in an indiscriminate way does not help me doing that. Also, in the large scheme of things, there are just a few ports that realistically benefit from parallel building. And those are often already tagged with DPB_PROPERTIES because they help the actual official package building.
