It looks like when we changed regress/GNUmakefile to pull rules from
Makefile.shlib, cygwin got broken in the process.
The problem is that regess.dll ends up being a symlink back to itself,
because we do a:
$(NAME)$(DLSUFFIX): $(shlib) rm -f $(NAME)$(DLSUFFIX) $(LN_S) $(shlib) $(NAME)$(DLSUFFIX)
And from Makefile.shlib (for cygwin)
ifeq ($(PORTNAME), cygwin) shlib = $(NAME)$(DLSUFFIX)
Thus regress.dll gets unhappy :-(
I don't know enough about the rest of the way the cygwin port is put
together, but it seems that the other platforms all have
shlib=lib$(NAME)...
-rocco