If pacman would allow you to install a package for a different architecture normally, perhaps it should warn users that it's installing a non-x86_64 package. Unlike some pacmage managers pacman doesn't use the architecture as part of the filename... ie no .i686.pkg.tar.gz or .x86_64.pkg.tar.gz. This would be difficult to change but perhaps a warning would be a simple solution to a possibly complex problem.
]]>But Arch64 will never have multilib support. So you won't be able to run 32bit apps if they need certain 32bit libs. If you want that go with one of the bloated multilib "intermediate" 64bit distros.
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