Dean, The source code for this problem case would be useful. The error messages suggest that the class HUnitClass.Charable is used at a point where the definition is not available. This probably indicates a compiler bug in placing the appropriate information into the interface files. Regards, Malcolm
Prelude> :l HUnit98Test [Std module... /stotts2/epa1/nhc98-1.08/rel/include/nhc98/Prelude.hi] [Found module... HUnit98Test.lhs] [Compiling... ***instanceI(1) InfoUsedClass 254 [(Type class,HUnitClass.Charable,"edulerP",0)] (Leaf2 (90,([],[]))) ***instanceI(1) InfoUsedClass 254 [(Type class,HUnitClass.Charable,"edulerP",0)] (Leaf2 (90,([],[]))) infoDepend InfoUsedClass 254 [(Type class,HUnitClass.Charable,"edulerP",0)] (Leaf2 (90,([],[]))) ...failed]