To mirror https://mirrors.kernel.org/sourceware/cygwin/ use following command line:
wget --no-verbose --no-check-certificate --content-disposition --mirror \
--no-parent --no-host-directories -e robots=off --continue https://mirrors.kernel.org/sourceware/cygwin/
Command above downloads files to ./sourceware/cygwin/
.
http://www.manpagez.com/man/1/wget/
$ wget --version
GNU Wget 1.13.4 built on cygwin.
+digest +https +ipv6 +iri +large-file +nls -ntlm +opie +ssl/gnutls