have you changed "use Foo1" to "use Foo2" in the script that calls the subroutine? Have you changed the name of the package to Foo2 as well?
What you are doing at the moment isn't object-oreinted code, so you should call the subroutine simply with Foo2::bar. Or just simply "bar()" because you exported "bar" from pacakge Foo2 into the local namespace of the script that uses Foo2.