--- aclocal.m4.orig	2012-06-24 11:38:45.000000000 +0200
+++ aclocal.m4.orig	2012-06-24 11:46:26.000000000 +0200
@@ -978,7 +978,12 @@ 
         # Clean out junk: http://bugs.python.org/issue3290
 	# Python headers may need some -f* flags, leave them in.
 	# We want the sed commands to look like 's/-[WDOm][[:alnum:][:punct:]][[:alnum:][:punct:]]*//g' and 's/-arch [^[:space:]]*//g', but automake eats brackets.
-	PYTHON_CFLAGS=`$PYTHON_CONFIG --cflags | sed -e 's/-[[WDOm]][[[:alnum:][:punct:]]][[[:alnum:][:punct:]]]*//g' | sed -e 's/-arch @<:@^@<:@:space:@:>@@:>@*//g'`
+	#PYTHON_CFLAGS=`$PYTHON_CONFIG --cflags | sed -e 's/-[[WDOm]][[[:alnum:][:punct:]]][[[:alnum:][:punct:]]]*//g' | sed -e 's/-arch @<:@^@<:@:space:@:>@@:>@*//g'`
+	# The above sed BRE matches parts of legal options, stipping down part of that option, resulting in invalid gcc arguments. Gentoo Bug #415793
+	# For instance, '-floop-stip-mime' becomes '-floop-strip', and '-fvect-cost-model' becomes '-fvect-cost'.
+	# Tentative fix to require a non alphanumeric character before the initial hyphen of the BRE.
+	# This is not perfect as the regex won't match with the first element of the python-config output
+	PYTHON_CFLAGS=`$PYTHON_CONFIG --cflags | sed -e 's/[[^[:alnum:]]]-[[WDOm]][[[:alnum:][:punct:]]][[[:alnum:][:punct:]]]*//g' | sed -e 's/-arch @<:@^@<:@:space:@:>@@:>@*//g'`
 	PYTHON_LDFLAGS=`$PYTHON_CONFIG --ldflags`
     fi