[ruby-core:68925] Need help building ruby trunk

Hello everyone,

I want to send a patch for Bug #11014 so I tried to build ruby trunk. When
I try to run ./configure from inside the ruby-trunk/build folder, I'm
getting this error
*configure: error: cannot run /bin/bash ../tool/config.sub*

I'm using ruby 2.2.0 and rbenv to manage my ruby versions. I also have
rbenv set up correctly. The /tool/config.sub file is filled with gibberish
that looks like this
^_�^H^@^@^@^@^@^@^C�}ks۸����Wp��u��l=,YN6{6;�9'ug�T^^u��(H∯!(Y�ʏ��^@@�^D�H�v���Gw^Ch^@�n<^_�Kp6��3�>x^\��gˏx�-Ï*γ`^W&���r;/�m^Ug"�Q^Y^Wճ)@^G^@_ܔ�j]^EÔ˔˔Q^?4^XN��J!�^O$
+�v^Y�^E�^]C^o�$�jL`�.vQ��2L��u^A^WA�^Q�u^@i�@^P�|^]'I0^W�V��69
^@^R�����^?���1x�����/ ^?����Ͽ^A�ZC�^Eb'�R�^VI^L��Le�U7�u@��տ�^_�^A^X/���ϯ?�
�^O~z��ͫ^O^_��

I'm following instructions I found on this page to build ruby trunk and run
unit tests -
http://ruby-doc.org/core-2.2.2/doc/contributing_rdoc.html#label-Running+tests

Has anyone else faced this problem? I'm contributing to MRI for the first
time so I don't really know how to find my way around.

Thanks,
Shishir