While trying to get Python 2.6 working on OpenBSD/sgi (64-bit port)
I ran into the following during build:

OverflowError: signed integer is greater than maximum

I ran the command that triggered this by hand with -v added:

(sgi Python-2.6.3 40)$ export PATH; PATH="`pwd`:$PATH";  export
PYTHONPATH; PYTHONPATH="`pwd`/Lib";  export DYLD_FRAMEWORK_PATH;
DYLD_FRAMEWORK_PATH="`pwd`";  export EXE; EXE="";  cd
./Lib/plat-openbsd4;  ./regen
python$EXE -v ../../Tools/scripts/h2py.py -i '(u_long)'
/usr/include/netinet/in.h
# installing zipimport hook
import zipimport # builtin
# installed zipimport hook
# /usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/site.pyc matches
/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/site.py
import site # precompiled from
/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/site.pyc
'import site' failed; traceback:
Traceback (most recent call last):
  File "/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/site.py", line 61,
in <module>
    import sys
OverflowError: signed integer is greater than maximum
import encodings # directory
/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/encodings
# /usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/encodings/__init__.pyc
matches /usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/encodings/__init__.py
import encodings # precompiled from
/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/encodings/__init__.pyc
Python 2.6.3 (r263:75183, Nov  6 2009, 09:50:33) 
[GCC 3.3.5 (propolice)] on openbsd4
Type "help", "copyright", "credits" or "license" for more information.
# /usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/re.pyc matches
/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/re.py
import re # precompiled from
/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/re.pyc
Traceback (most recent call last):
  File "../../Tools/scripts/h2py.py", line 24, in <module>
    import sys, re, getopt, os
  File "/usr/obj/ports/Python-2.6.3/Python-2.6.3/Lib/re.py", line 104,
in <module>
    import sys
OverflowError: signed integer is greater than maximum
# clear __builtin__._
# clear sys.path
# clear sys.argv
# clear sys.ps1
# clear sys.ps2
# clear sys.exitfunc
# clear sys.exc_type
# clear sys.exc_value
# clear sys.exc_traceback
# clear sys.last_type
# clear sys.last_value
# clear sys.last_traceback
# clear sys.path_hooks
# clear sys.path_importer_cache
# clear sys.meta_path
# clear sys.flags
# clear sys.float_info
# restore sys.stdin
# restore sys.stdout
# restore sys.stderr
# cleanup __main__
# cleanup[1] zipimport
# cleanup[1] signal
# cleanup[1] exceptions
# cleanup[1] _warnings
# cleanup sys
# cleanup __builtin__
# cleanup ints: 3 unfreed ints
# cleanup floats
(sgi plat-openbsd4 41)$

There have been several patches applied:
http://www.openbsd.org/cgi-bin/cvsweb/ports/lang/python/2.6/patches/
Although none seem to be relevant as far as I can see.

Please find attached the build log and the configure log.