The recent 'mmshell' change to bin/Makefile.in causes a problem in Cygwin (I really have to make a 'real' test platform one of these days, but that's another story).

The change adds

for f in $(LN_SCRIPTS); \
do \
    rm -f $(DESTDIR)/$(SCRIPTSDIR)/$$f; \
    (cd $(DESTDIR)/$(SCRIPTSDIR); $(LN_S) mmshell $$f); \
done

This should really be

for f in $(LN_SCRIPTS); \
do \
    rm -f $(DESTDIR)$(SCRIPTSDIR)/$$f; \
    (cd $(DESTDIR)$(SCRIPTSDIR); $(LN_S) mmshell $$f); \
done

DESTDIR is normally null and SCRIPTSDIR is $(prefix)/bin. With the extra slash, this creates a path that on Cygwin winds up looking in my case like '//cygdrive/f/test-mailman/bin'. Normally, the doubled slash wouldn't matter, but /cygdrive/f is not a real directory, it is a magic construct that refers to the root of the F: drive, and //cygdrive/f doesn't work.