The galois_raytrace test requires the parsec package

testsuite/tests/ghc-regress/programs/galois_raytrace/test.T

 setTestOpts(omit_compiler_types(['hugs']))	# takes much too long
 
 test('galois_raytrace', \
-	skip_if_fast, \
+	compose(skip_if_fast, reqlib('parsec')), \
 	multimod_compile_and_run, \
 	['Main','-package parsec'])
 clean_o_hi()