because re-opening STDERR decouples perl's STDERR from the called C library's STDERR

It will probably work if you save/dup STDERR and restore it 

open my $errsave, '>&', STDERR
  or do { print "couldn't dup STDERR: $!"; exit 2; };
open STDERR ...
...
open STDERR, '>&', $errsave
  or do { print "couldn't restore/dup STDERR: $!"; exit 2; };

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In reply to Re^3: STDERR going to string by Anonymous Monk
in thread STDERR going to string by philkime

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