https://bugs.winehq.org/show_bug.cgi?id=50258
--- Comment #3 from Gijs Vermeulen gijsvrm@gmail.com --- (In reply to joaopa from comment #2)
It looks like that even if WINARCH=win32 is appended, a 64 bit prefix is created.
Just to be sure, you meant WINEARCH, right? If so, that would be a bug, otherwise you just misspelled the variable.