Demo of issue with proc_open dropping hyphenated environment variables

proc_open_test.php

<?php

putenv('INNER=aeiou');
putenv('INNER-VAR=aeiou');

#echo PHP_EOL, '-- REQUIRE_ONCE START --', PHP_EOL, PHP_EOL;
#require_once('proc_open_test_helper.php');
#echo PHP_EOL, '-- REQUIRE_ONCE END --', PHP_EOL, PHP_EOL;

echo PHP_EOL, '-- SUBPROCESS START --', PHP_EOL, PHP_EOL;

$descriptorspec = array(
   0 => array('file', '/dev/null', 'r'),
   1 => array('pipe', 'w'),
   2 => array('file', '/dev/null', 'a')
);

$process = proc_open('php proc_open_test_helper.php', $descriptorspec, $pipes);

if (!is_resource($process)) {
    die('Failed to create process!');
}

echo stream_get_contents($pipes[1]);
fclose($pipes[1]);

$return_value = proc_close($process);
echo "command returned $return_value", PHP_EOL;

echo PHP_EOL, '-- SUBPROCESS END --', PHP_EOL, PHP_EOL;

proc_open_test_helper.php

<?php
echo 'A-B=', getenv('A-B'), PHP_EOL;
echo 'FOO=', getenv('FOO'), PHP_EOL;

echo 'getenv("INNER"): ', getenv("INNER"), PHP_EOL;
echo 'getenv("INNER-VAR"): ', getenv("INNER-VAR"), PHP_EOL;

echo 'done', PHP_EOL;

run.sh

env 'A-B=ZZZ' 'FOO=BAR' php proc_open_test.php