The 'cygcheck-dep -l' output also lists various packages which are 
actually required by other packages.

Testcase:

$ cygcheck -f /bin/cygcheck-dep
cygcheck-dep-2.0-1

$ cygcheck-dep -c -N ncursesw
  ncursesw: is recursively needed for ( )

$ cygcheck-dep -c -N ncurses
  ncurses: is recursively needed for ( ncursesw )

$ cygcheck-dep -c -l | grep '^ ncurses'
  ncurses
  ncursesw

The attached patch should fix that.

Christian