Nice hint, yeah that helped me find it:

index 9ff94aa..63b3fdf 100644
--- a/gdb/python/lib/gdb/printer/bound_registers.py
+++ b/gdb/python/lib/gdb/printer/bound_registers.py
@@ -25,7 +25,7 @@ class MpxBound128Printer:
     def to_string (self):
         upper = self.val["ubound"]
         lower = self.val["lbound"]
-        size  = (long) ((upper) - (lower))
+        size  = (int) ((upper) - (lower))
         if size > -1:
             size = size + 1
         result = '{lbound = %s, ubound = %s} : size %s' % (lower, upper, size)

I'll submit that patch to gdb, that fixed the exception.

Thanks,
-Doug

On Sun, Feb 14, 2016 at 11:20 AM, immerrr again <immerrr@gmail.com> wrote:
On Sun, Feb 14, 2016 at 9:11 PM, Eli Zaretskii <eliz@gnu.org> wrote:
>>
>> Breakpoint 1, 0x000000000040053a in main ()
>> (gdb) Python Exception <class 'NameError'> name 'long' is not defined:
>> Python Exception <class 'NameError'> name 'long' is not defined:
>> Python Exception <class 'NameError'> name 'long' is not defined:
>> Python Exception <class 'NameError'> name 'long' is not defined:
>>

NameError means something is undefined, so probably gdb is executing
scripts using python3 and some script doesn't account for the fact
that only "long" and "int" types got merged  in Python3 world and
"long" no longer exists.