building with cygwin

[Nicolas Rybkin <mfkorenev yandex ru>]

Hi, did anyone try to compile stuff with cygwin?
./configure gives:
configure: error: S-Lang library version 2.0 or newer not found
I have cygslang-2.dll in /bin. I really can't learn from configure script how it tests slang presence, 
there's "test x"$ac_slang_lib_path"" and something like and I don't know what this "test" does.
Also can anyone tell me how to use cygport?
cygport slang-2.2.2-2.cygport download
gives:
*** ERROR: diff is required to run cygport
what diff?