Make sure unification errors for incompatible types when we don't have free variables
Make sure unification errors for incompatible types when we don't have free variables

FrancescAlted/datashape,markflorisson/datashape,cpcloud/datashape,ContinuumIO/datashape,quantopian/datashape,ContinuumIO/datashape,quantopian/datashape,FrancescAlted/datashape,llllllllll/datashape,cowlicks/datashape,blaze/datashape,cpcloud/datashape,cowlicks/datashape,markflorisson/datashape,llllllllll/datashape,aterrel/datashape,aterrel/datashape,blaze/datashape