From: Urabe Shyouhei <shyouhei@...>
Date: 2010-11-29T10:56:16+09:00
Subject: [ruby-core:33455] Re: Planning to release 1.8.7 fixes on 12/25 (Japanese timezone)

(2010/11/29 9:53), Luis Lavena wrote:
>           Config::MAKEFILE_CONFIG["top_srcdir"] = $top_srcdir =
> "../ruby" unless e; \

Curious.  You get the exact same error message as you pasted in #4094 ?
It seems your source directory is ../ruby so ../ruby/ruby.h should exist and
the error will not raise.