Comment 25 for bug 990982

Out of interest, I installed 18.04 in a VM and had no problems installing the multi-arch libfreetype6-dev packages for and64 and i386.

That said, you’re largely out of luck when it comes to building Wine from source on 18.04. Even the most recent point release (18.04.6) is limited by many build-dependencies not being multi-arch ready.

Multi-arch support really improved after 18.04. I’m afraid you’ll need to migrate to 20.04 or more recent.