id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
50	Emit error for dangerous vars at top level.	benl		"Exporting mutable data containing monomorphic type vars is not sound because two different modules might update it at different types. 

At the moment we seem to silently default such types to Unit.
{{{
thing 	:: forall a. Ref %r1 (a -> a)
	:- Mutable %r1

thing	= Ref id
}}}

In the .di file we get
{{{
foreign import thing
        :: Base.Ref %r1 (Base.Unit -> Base.Unit)
        :- Base.Mutable %r1
        ,  Base.Direct %r1
        :$ Base.Data;
}}}

"	defect	new	normal	0.1.5	Source Type Inferencer	0.1.2