../POE/kernel.pm
...
 {
    no strict 'refs';
    if ($^O eq 'MSWin32') {
        *{ __PACKAGE__ . '::RUNNING_IN_HELL' } = sub { 1 };
    } else {
        *{ __PACKAGE__ . '::RUNNING_IN_HELL' } = sub { 0 };
    }
...
.../POE/Resource/FileHandles.pm

BEGIN {
  eval 'F_GETFL';
  if ($@) {
    *F_GETFL = sub () { 0 };
    *F_SETFL = sub () { 0 };
  }