Crashing when writing to file

[JLiangWaterloo]

X
    x:int
        y
            z
                [x > 0]

Run the above model.

clafer -o Test outputs correctly to the console

clafer Test runs into the following error

Parse Successful!
[Desugaring]
[Resolving]
[Analyzing String]
[Optimizing]
[Generating Code]
All clafers: 4 | Abstract: 0 | Concrete: 4 | References: 0
Constraints: 1
Global scope: 1..1
All names unique: True

[Saving File]
clafer: Prelude.tail: empty list

[kbak]

Fixed. The translator assumed that name always has extension.