parse error in anonymous function

[A1-Mathematik]

This seems inconsistent (from discourse ):

julia> function(a::Int)::Bool end
ERROR: syntax: ambiguous signature in function definition. Try adding a comma if this is a 1-argument anonymous function.
Stacktrace:
 [1] top-level scope
   @ none:1

julia> function(a::Int,)::Bool end
ERROR: syntax: ambiguous signature in function definition. Try adding a comma if this is a 1-argument anonymous function.
Stacktrace:
 [1] top-level scope
   @ none:1

julia> VERSION
v"1.8.0-DEV.94"