Per the wiki at https://wiki.winehq.org/Building_Wine#Shared_WoW64
"if you do choose to install your WoW64 build, you should run make
install in the 32-bit build tree first, then in the 64-bit one."
This is required, for instance, for the resulting "wineserver"
executable to be the 64 bit variant not 32 bit. Which is expected by the
binary loader for WoW64.
This odd dependency is vaguely mentioned on the packaging wiki page:
* https://wiki.winehq.org/Packaging#Binaries