Error found:
in module Main
at tests/purs/failing/CoercibleUnknownRowTail1.purs:7:9 - 7:24 (line 7, column 9 - line 7, column 24)

  No type class instance was found for
                            
    Prim.Coerce.Coercible ()
                          t0
                            
  The instance head contains unknown type variables. Consider adding a type annotation.

while solving type class constraint
                                  
  Prim.Coerce.Coercible { a :: Int
                        }         
                        { a :: Int
                        | t0      
                        }         
                                  
while applying a function coerce
  of type Coercible @Type t1 t2 => t1 -> t2
  to argument { a: 0
              }     
while checking that expression coerce { a: 0
                                      }     
  has type { a :: Int
           | t0      
           }         
while checking type of property accessor (coerce { a: ...
                                                 }       
                                         )               
                                         .a              
in value declaration zero

where t0 is an unknown type
      t1 is an unknown type
      t2 is an unknown type

See https://github.com/purescript/documentation/blob/master/errors/NoInstanceFound.md for more information,
or to contribute content related to this error.