http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD

If the version you run (./config.guess) is already up to date, please
send the following data and any information you think might be
pertinent to <config-patches@gnu.org> in order to provide the needed
information to handle your system.

config.guess timestamp = 2013-06-10

uname -m = x86_64
uname -r = 2.0.0(0.271/5/3)
uname -s = MSYS_NT-6.1
uname -v = 2014-02-16 19:55

/usr/bin/uname -p = unknown
/bin/uname -X     = 

hostinfo               = 
/bin/universe          = 
/usr/bin/arch -k       = 
/bin/arch              = x86_64
/usr/bin/oslevel       = 
/usr/convex/getsysinfo = 

UNAME_MACHINE = x86_64
UNAME_RELEASE = 2.0.0(0.271/5/3)
UNAME_SYSTEM  = MSYS_NT-6.1
UNAME_VERSION = 2014-02-16 19:55
configure: error: cannot guess build type; you must specify one
checking build system type...