Issue #8020 has been updated by phasis68 (Heesob Park).


This issue only occurs with autoconf 2.64.
The workaround is using quadrigraphs.

Here is a patch:
diff --git a/configure.in b/configure.in.new
index 4d6d6ed..b4f11b7 100644
--- a/configure.in
+++ b/configure.in.new
@@ -625,7 +625,7 @@ AC_ARG_ENABLE(werror,
 	AS_HELP_STRING([--disable-werror],
 		       [don't make warnings into errors
 		       even if a compiler support -Werror feature
-		       [[disabled by default unless development version]]]),
+		       @<:@disabled by default unless development version@:>@]),
 	[particular_werror_flags=$enableval])
 
 rb_cv_warnflags="$warnflags"

----------------------------------------
Bug #8020: make-snapshot fails since r39221
https://bugs.ruby-lang.org/issues/8020#change-37323

Author: phasis68 (Heesob Park)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: ruby 2.0.0dev (2012-11-08 trunk 37564) [i686-linux]


$ ruby tool/make-snapshot /tmp/snapshopt trunk@39221
Exporting trunk@39221
Exported revision 39221.
take a breath, and go ahead
creating configure...configure:1507: error: possibly undefined macro: _m4_text_wrap_word
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
 failed


$ autoconf --version
autoconf (GNU Autoconf) 2.64
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv2+: GNU GPL version 2 or later
<http://gnu.org/licenses/old-licenses/gpl-2.0.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by David J. MacKenzie and Akim Demaille.
---
Autoconf 2.50 chosen by Debian wrapper script.
For information and tuning advice see autoconf(1).


I am not sure where it is related to the same issue, the Nightly Snapshot(ftp://ftp.ruby-lang.org/pub/ruby/snapshot.tar.gz) is not generated since 2013/02/28 04:09:14.



-- 
http://bugs.ruby-lang.org/