Hi, 

From: Joel VanderWerf <joelvanderwerf / gmail.com>
Subject: building ext/tk on Ubuntu 14.04
Date: Sat, 09 Aug 2014 15:34:42 -0700
Message-ID: <53E6A202.7050106 / gmail.com>

> I don't know why the packaged tk8.5 doesn't work, even with all
> relevant CONFIGURE_ARGS set for extconf.rb.

Would you try to give proper options for tcltklib decribed in 
"ext/tk/README.tcltklib" ?
tcltklib.so should be compiled, when extconf.rb finds proper 
tclConfig.sh/tkConfig.sh by auto or configure options.
If multiple versions of Tcl/Tk on your environment, please teach 
the proper files by configure options.

When you fail to compile even if give enough options,
please report messages and logs.
-- 
Hidetoshi NAGAI (nagai / ai.kyutech.ac.jp)
Department of Artificial Intelligence, Kyushu Institute of Technology