-- -stubdir D adds an implicit -I D, so that gcc can find the _stub.h file
  -- \#included from the .hc file when compiling with -fvia-C.
setOutputDir  f = setObjectDir f . setHiDir f . setStubDir f
setOutputDir  f = setObjectDir f . setHiDir f . setStubDir f
setOutputDir  f = setObjectDir f . setHiDir f . setStubDir f