If you open a pipe in a parent process via open(), then spawn a child, which then runs the close() on the open handle, close() fails with "No child processes":

open PIPE, "| cat" or die $!;

my $pid = fork();

if( $pid == 0 ) {
    # child
    close PIPE or die $!;
    exit 0;
}

sleep 1;
my $reaped = waitpid(-1, 0 );
print "pid $reaped\n";
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Now you'll certainly say "Don't do that!" but the problem is that the open() happens in a module I maintain and the close() happens in its DESTROY method. If the user of the module decides that they want to spawn a child process, the error occurs! Who's to blame here? The module? The user? Perl? Should every module opening a pipe implement logic to check if the close fails for this obscure reason and suppress an error that's otherwise reported and will confuse the user?

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