Good catch, thanks@xabbuh.

@nicolas-grekas We'll fix it this week 👍

We rebuilt with the latest 8.5 version but it still crashing. Might just have to consider 8.5 unstable until it's RC1.

For a bit more context, it looks decidedly like anABI problem.

Building Relay inside the container fixes the problem and so does using a different source image. Unfortunately there is nothing obviously wrong with our 8.5 builds (e.g. warnings due to changing PHP internals).

I'm still going to try and pinpoint the issue, but at the very least we'll make sure it's working/fixed when 8.5 is released.