Finally fix this problem:
make: *** No rule to make target `Text/Regex/Posix_hsc_make.c', needed by `depend'. Stop.
caused by temporary droppings from hsc2hs.
$(patsubst %.gc, %_stub_ffi.h, $(GC_SRCS))
endif
+# These are droppings from hsc2hs - ignore them if we see them.
+EXCLUDED_C_SRCS = $(patsubst %.hsc, %_hsc_make.c, $(HSC_SRCS))
+
C_SRCS = $(filter-out $(EXCLUDED_C_SRCS),$(filter %.c,$(SRCS)))
C_OBJS = $(addsuffix .$(way_)o,$(basename $(C_SRCS)))