rvar failed to build: Couldn't match type ‘MutableGen f0 (RVarT m)’ with ‘RGen’

[juhp]

Stackage Nightly:

       /home/curators/work/unpack-dir/unpacked/rvar-0.3.0.2-2a30fee29999a4593c737c6077d889c0cec106800210cb7ec781e6228bf97439/src/Data/RVar.hs:270:10: error: [GHC-18872]
           • Couldn't match type ‘MutableGen f0 (RVarT m)’ with ‘RGen’                                                                                                                   
               arising from a use of ‘System.Random.Internal.$dmuniformByteArrayM’                                                                                                       
             The type variable ‘f0’ is ambiguous                                            
           • In the expression:               
               System.Random.Internal.$dmuniformByteArrayM @RGen @(RVarT m)                                                                                                              
             In an equation for ‘uniformByteArrayM’:                                        
                 uniformByteArrayM                                                          
                   = System.Random.Internal.$dmuniformByteArrayM @RGen @(RVarT m)                                                                                                        
             In the instance declaration for ‘StatefulGen RGen (RVarT m)’                                                                                                                
           • Relevant bindings include                                                      
               uniformByteArrayM :: Bool                                                    
                                    -> Int -> RGen -> RVarT m Data.Array.Byte.ByteArray                                                                                                  
                 (bound at src/Data/RVar.hs:270:10)                                         
           |                                  
       270 | instance StatefulGen RGen (RVarT m) where                                      
           |          ^^^^^^^^^^^^^^^^^^^^^^^^^^