http://thread.gmane.org/gmane.comp.sysutils.automake.patches/8572

--- lib/am/distdir.am	2009-12-08 18:15:40.000000000 +0000
+++ lib/am/distdir.am.oden	2012-07-12 09:50:14.000000000 +0000
@@ -441,7 +441,7 @@ distcheck: dist
 ## Make the new source tree read-only.  Distributions ought to work in
 ## this case.  However, make the top-level directory writable so we
 ## can make our new subdirs.
-	chmod -R a-w $(distdir); chmod a+w $(distdir)
+	chmod -R a-w $(distdir); chmod u+w $(distdir)
 	mkdir $(distdir)/_build
 	mkdir $(distdir)/_inst
 ## Undo the write access.