Phoronix Test Suite "Allowed Memory Size Exhausted" under 22.04

I installed Phoronix Test Suite 10.8.4 on Ubuntu 22.04 using the deb package from their website. Up until a couple of weeks ago, it worked without issues. Now when I run a benchmark, I get an error like this:

Started Run 1 @ 11:29:41PHP Fatal error:  Allowed memory size of 1073741824 bytes exhausted (tried to allocate 534773792 bytes) in /usr/share/phoronix-test-suite/pts-core/objects/client/pts_test_execution.php on line 298

PTS depends on PHP, and I noticed in /var/log/apt/history.log, there were several updates to PHP (to 8.1.2-1ubuntu2.9). I checked my /etc/php/8.1/cli/php.ini file and the memory_limit is set to -1, so that doesn't seem to be the problem. Does anyone know what change might have caused the problem that I'm seeing, or how I might fix this?

Edit: This is the block where PTS is failing (Edit edit: the right line). It's failing on the $test_result_std_output = stream_get_contents($pipes[1]); line.

  if(is_resource($test_process))
  {       
    //echo proc_get_status($test_process)['pid'];
    pts_module_manager::module_process('__test_running', $test_process);
    $test_result_std_output = stream_get_contents($pipes[1]);
    fclose($pipes[1]);
    fclose($pipes[2]);
    $return_value = proc_close($test_process);
  }