title: How to solve configure checking
body: <p>Nowdays I'm just trying to build libsamperate from source using MSYS on Windows, but i meet a configure checking problem I've installed FFTW &amp; libsndfile before, their include files lib files and pkg-config files are all in the right place, but when I use sh <code>./configure</code> to generate makefile for libsamprate the output always mentions</p>
  
  <pre><code>checking for pkg-config... no
  checking for SNDFILE... no
  </code></pre>
  
  <p>I also set the PKG_CONFIG_PATH(usr/local/lib/pkgconfig) and tried many times but the result seems the same</p>
  
  <p>Does anyone knows anything about this?</p>