webkit-sodium failed to be built in ghcjs-8.6.0.1 and ghcjs-dom-0.9.4.0

[YuMingLiao]

The error message is posted here 798

It seems webkit-sodium couldn't use the latest ghcjs-dom interface.

Engine.hs in webkit-sodium change its imports for ghcjs-dom in commit 43d63e2.

But I couldn't find such interfaces in older ghcjs-dom version.