Patch #429442 from Jason Tishler: Corrects sys.platform and

distutils.util.get_platform() problems caused by the cruft contained
    in Cygwin's uname -s.

Lib/distutils/util.py

@@ -62,6 +62,7 @@ def get_platform ():
     elif osname[:3] == "aix":              
         return "%s-%s.%s" % (osname, version, release)
     elif osname[:6] == "cygwin":
+        osname = "cygwin"
         rel_re = re.compile (r'[\d.]+')
         m = rel_re.match(release)
         if m:

configure.in

@@ -64,6 +64,7 @@ then
 	MACHDEP="$ac_md_system$ac_md_release"
 
 	case $MACHDEP in
+	cygwin*) MACHDEP="cygwin";;
 	'')	MACHDEP="unknown";;
 	esac
 fi