title: Error installing GMP on cygwin "configure: error: could not find a working compiler, see config.log for details"
body: <p>I got the following error in configuring GMP while building a bare metal GNU cross toolchain for Xtensa on cygwin</p>
  
  <p>configure: error: could not find a working compiler, see config.log for details</p>
  
  <p>The build was performed using a crosstool-NG downloaded from the site <a href="http://wiki.linux-xtensa.org/index.php/Crosstool-NG" rel="nofollow">http://wiki.linux-xtensa.org/index.php/Crosstool-NG</a> using the git clone git clone <a href="https://github.com/foss-xtensa/crosstool-NG.git" rel="nofollow">https://github.com/foss-xtensa/crosstool-NG.git</a></p>
  
  <p>This downloads GMP-5.1.1 while downloading GCC and related packages.</p>
  
  <ol>
  <li><p>Build environment - cygwin</p></li>
  <li><p>The GMP version number - GMP-5.1.1</p></li>
  <li><p>Output of gcc -v</p>
  
  <pre><code>$ gcc -v
  Using built-in specs.
  COLLECT_GCC=gcc
  COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-pc-cygwin/4.9.3/lto-wrapper.exe
  Target: i686-pc-cygwin
  Configured with: /cygdrive/i/szsz/tmpp/gcc/gcc-4.9.3-1.i686/src/gcc-   4.9.3/configure --srcdir=/cygdrive/i/szsz/tmpp/gcc/gcc-4.9.3-1.i686/src/gcc-4.9.3 --prefix=/usr --exec-prefix=/usr --localstatedir=/var --sysconfdir=/etc --docdir=/usr/share/doc/gcc --htmldir=/usr/share/doc/gcc/html -C --build=i686-pc-cygwin --host=i686-pc-cygwin --target=i686-pc-cygwin --without-libiconv-prefix --without-libintl-prefix --libexecdir=/usr/lib --enable-shared --enable-shared-libgcc --enable-static --enable-version-specific-runtime-libs --enable-bootstrap --enable-__cxa_atexit --with-dwarf2 --with-arch=i686 --with-tune=generic --disable-sjlj-exceptions --enable-languages=ada,c,c++,fortran,java,lto,objc,obj-c++ --enable-graphite --enable-threads=posix --enable-libatomic --enable-libgomp --disable-libitm --enable-libquadmath --enable-libquadmath-support --enable-libssp --enable-libada --enable-libjava --enable-libgcj-sublibs --disable-java-awt --disable-symvers --with-ecj-jar=/usr/share/java/ecj.jar --with-gnu-ld --with-gnu-as --with-cloog-include=/usr/include/cloog-isl --without-libiconv-prefix --without-libintl-prefix --with-system-zlib --enable-linker-build-id
  Thread model: posix
  gcc version 4.9.3 (GCC)
  </code></pre></li>
  <li><p>The output from running ‘uname -a’.</p>
  
  <pre><code>$ uname -a
  CYGWIN_NT-6.1 si-hnhari 2.1.0(0.287/5/3) 2015-07-14 21:26 i686 Cygwin
  </code></pre></li>
  </ol>
  
  <p>The output of config.log and build.log is attached.</p>
  
  <p>Please let me know if you need any more information.</p>
  
  <p>Thanks and Regards,
  Hari</p>