I uncovered some more information on this problem. While the test code I originally posted didn't report anythingon the segfault, this code...

#!/usr/bin/perl -w
use strict;
use Filter::Handle qw/subs/;

Filter \*STDOUT,
    sub { local $_ = "@_"; s/blue/red/g; $_ };

print "My house is blue.\n";
print "So is my cat, whose nose is blue.\n";

UnFilter \*STDOUT;

print "And the plane is also blue.\n";
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... gave me a "Deep recursion on subroutine "Filter::Handle::PRINT" at /Library/Perl/5.8.6/Filter/Handle.pm line 42." That gave me some clues, but what I thought was the solution isn't working.

Here is the subroutine with line 42 in it.

sub PRINT {
    my $self = shift;
    my $fh = *{ $self->{fh} };
    print $fh, $self->{output}->(@_);
}
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The last line in #42. Immediately I thought perl is getting confused to which print to call and going into an infinite loop until a segfault happens. Thing is prepending CORE:: still ends in the same results.

sub PRINT {
    my $self = shift;
    my $fh = *{ $self->{fh} };
    CORE::print $fh $self->{output}->(@_);
}
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I also added a "use subs" for print and printf to no avail.

use subs qw(print printf);
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My experiments with Tie::Handle have return similar results so far.

What is happening here to confuse Perl that it goes into an infinite loop? Why is the use of CORE:: getting ignored or changed by this code?

Any ideas would be appreciated.