I haven't really looked into this before, that's why it hangs here still. As a side note I would add that the RESTEASY info is a lot more detailed in description than this one, which might be yet another reason why it was quickly resolved.
And you probably misunderstood me, I am not diminishing/closing this issue at all. Quite the opposite, I think its relevant but I want to fully understand the extent to which it affects Weld. I got the impression this is just a first of many Java 9 issues to show up with modularization.

Question like these pop up:
1) Is this the only "package clash" we have in Weld? How do we easily determine this?
2) What do we do in Weld 2.4, we probably want ppl to run it on Java 9 (and if we don't want it, EAP will want it) but this change is not backward compatible to put it there.
3) Then there is Maven and its module-path. Why can't we determine between CP and MP - Java 9 operates on both (e.g. automatic modules versus unnamed module)

• actually this Maven stuff would vastly address second point and maybe affect even more things but I cannot really get enough information on that

Anyway, again saying that this issue is relevant and the PR will get merged. We will then address other issues in separate tickets.