Bug 1512822 will require that we use at least LLVM 8.0.0 rc1.

The sidebar on llvm.org's front page is currently projecting:

8.0.0:
Jan 16: Branch point, rc1
Feb 6: rc2
Feb 27: final

(Though historically the dates have not always been exact.)

According to the Firefox release calendar, we have merge days on 2019-01-28 (Fx67) and 2019-03-18 (Fx68).

I propose that in the first days of Firefox 67, we take whatever LLVM RC is current, and later within 67 pick up the final release.

I'm getting the following linker error in libxul when trying to build with rc1 and ThinLTO:

LLVM ERROR: Associative COMDAT symbol '??_7MaxExpSink@?A0xC8782BCA@icu_63@@6B@' does not exist.

(In reply to Michael Woerister from comment #2)

I'm getting the following linker error in libxul when trying to build with
rc1 and ThinLTO:

LLVM ERROR: Associative COMDAT symbol
'??_7MaxExpSink@?A0xC8782BCA@icu_63@@6B@' does not exist.

Do you have a link to a try push? (Not necessary but it would be the most concise way to reproduce your state.) Otherwise, can you share your mozconfig, LLVM and Mozilla revisions, and any patches you have applied?

Now I do: https://treeherder.mozilla.org/#/jobs?repo=try&revision=a0ecb434e9eebf773ceedb4d1691a1e23cb4e48d

Bisected and filed: https://bugs.llvm.org/show_bug.cgi?id=40414

https://hg.mozilla.org/mozilla-central/rev/bb99a5af0154