Namespace conflict in Diagrams.TwoD.Layout.Tree

[akhra]

D:\diagrams-contrib\src\Diagrams\TwoD\Layout\Tree.hs: line 187, column 18:
  Ambiguous occurrence `Empty'
    It could refer to either `Diagrams.TwoD.Layout.Tree.Empty',
                             defined at src\Diagrams\TwoD\Layout\Tree.hs:182:16
                          or `Diagrams.Prelude.Empty',
                             imported from `Diagrams.Prelude' at src\Diagrams\TwoD\Layout\Tree.hs:163:1-33
                             (and originally defined in `Control.Lens.Empty')
D:\diagrams-contrib\src\Diagrams\TwoD\Layout\Tree.hs: line 187, column 24:
  Ambiguous occurrence `Empty'
    It could refer to either `Diagrams.TwoD.Layout.Tree.Empty',
                             defined at src\Diagrams\TwoD\Layout\Tree.hs:182:16
                          or `Diagrams.Prelude.Empty',
                             imported from `Diagrams.Prelude' at src\Diagrams\TwoD\Layout\Tree.hs:163:1-33
                             (and originally defined in `Control.Lens.Empty')

Empty is both defined locally (for the BTree type) and imported from lens via Diagrams.Prelude. This breaks compilation for me, both from Hackage (1.3.0.6) and GitHub (1.3.1).

[byorgey]

Thanks! I wonder how we missed that.