Patch #403947: On Cygwin, use the Unix compiler class, and not
 the Cygwin-specific compiler class.

 (According to Jason Tishler, cygwinccompiler needs some work to
  handle the differences in Cygwin- and MSVC-Python. Makefile and
  config files are currently ignored by cygwinccompiler, as it was
  written to support cygwin for extensions which are intended to be
  used with the standard MSVC built Python.)
diff --git a/Lib/distutils/ccompiler.py b/Lib/distutils/ccompiler.py
index 0a30640..4a282d4 100644
--- a/Lib/distutils/ccompiler.py
+++ b/Lib/distutils/ccompiler.py
@@ -842,7 +842,10 @@
 _default_compilers = (
 
     # Platform string mappings
-    ('cygwin.*', 'cygwin'),
+
+    # on a cygwin built python we can use gcc like an ordinary UNIXish
+    # compiler
+    ('cygwin.*', 'unix'),
     
     # OS name mappings
     ('posix', 'unix'),