Symbol omission in PerlStub (MacPerl 5.6.1b3)

It appears that in the version of 'stdio.h' in 'Sfio01Aug99' that 
'sprintf' and 'sscanf' are re-defined as '_stdsprintf' and 'sfsscanf' 
respectively.

The symbol '_stdsprintf' turns up in 'perl.exp' (and hence in 
'PerlStub') but 'sfsscanf' seems not to be exported and is not in 
'PerlStub'.

The upshot is that XS builds which involve  the 'C' function 
'sscanf()' fail because the linker cannot find the symbol 'sfsscanf' 
in 'PerlStub'.

Does anyone agree this is a bug? Or is there a work-around?

Alan Fry