Record types require too much indentation

[LightAndLight]

When I wrote a type signature like this:

parseUri : 
  String -> 
  (| 
    Object : { hash : String },
    Blob : { hash : String },
    Commit : { 
      hash : String,
      path : (|
        None : (),
        Tree : Array String,
        Parent : Array String
      |)
    },
    Tree : { hash : String },
    Error : String
  |)

I got an error:

error: expected one of: indent (>= 13)
   |
xx |       hash : String,
   |       ^

The type I wrote should be syntactically valid.