OK, thanks.  The closefd part is good, but the stderrprinter part has a
problem.  On Linux, in a non-debug build, this has the odd side effect
of subtracting one from sys.maxunicode.  In a debug build, it dies like
this: 

$ ./python -S
python: Modules/gcmodule.c:336: visit_reachable: Assertion `gc_refs > 0
|| gc_refs == (-3) || gc_refs == (-2)' failed.
Aborted
$ 

If I comment out the PySys_SetObject() call everything seems fine, but I
suspect that the problem is actually in the creation of the stdprinter
object.