On a solaris 9 box, also running 5.8.8, same result:

$ perl -we 'open O, "> /dev/null"; print O (scalar readline)'
Filehandle O opened only for output at -e line 1.
Bus Error
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On Cygwin w/5.8.7, the same thing happens, but interestingly enough the warn readline(); example posted below doesn't trigger:

$  perl -we 'open O, "> /dev/null"; print O (scalar readline)'
Filehandle O opened only for output at -e line 1.
     11 [main] perl 4756 _cygtls::handle_exceptions: Error while dumpi
+ng state (
probably corrupted stack)
Segmentation fault (core dumped)

$ perl -e 'warn readline()'
Warning: something's wrong at -e line 1.
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