Please quote your code with backticks
This is indeed confusing and is a real change since earlier Julia versions: https://github.com/JuliaLang/julia/issues/15602#issuecomment-200410836
Fortunately, it’s also very easy to fix by using an anonymous function instead (which will perform just as well):
julia> function t()
f = () -> 1
print(f())
f = () -> 2
print(f())
end
t (generic function with 1 method)
julia> t()
12