I wonder which commit introduced this regression which used to work 
before (I think till rc1).

This error occurs on solaris10-x86, solaris8-sparc, solaris8-sparc64 
and aix5-powerpc.

(...)
ranlib libpython3.1.a
cc   -o python \
                Modules/python.o \
                libpython3.1.a -lresolv -lsocket -lnsl -lintl -lrt -
ldl   -lm  
Fatal Python error: Py_Initialize: can't initialize sys standard streams
IOError: [Errno 29] Illegal seek
*** Error code 134
The following command caused the error:
case $MAKEFLAGS in \
*s*)  CC='cc' LDSHARED='cc -G' OPT='-DNDEBUG -O' ./python -E ./setup.py 
-q build;; \
*)  CC='cc' LDSHARED='cc -G' OPT='-DNDEBUG -O' ./python -E ./setup.py 
build;; \
esac
make: Fatal error: Command failed for target `sharedmods'


Entire build log (solaris10-x86) is attached.