Задать переменную COMPOSER_HOME для composer

cat <<\x | /c/srv/usr/php74/php
<?php
function executeCommand($command)
{
    $descriptors = array(
        0 => array("pipe", "r"), // stdin - read channel
        1 => array("pipe", "w"), // stdout - write channel
        2 => array("pipe", "w"), // stdout - error channel
        3 => array("pipe", "r"), // stdin - This is the pipe we can feed the password into
    );
    $process = proc_open($command, $descriptors, $pipes);
    if (!is_resource($process)) {
        die("Can't open resource with proc_open.");
    }
    // Nothing to push to input.
    fclose($pipes[0]);
    $output = stream_get_contents($pipes[1]);
    fclose($pipes[1]);
    $error = stream_get_contents($pipes[2]);
    fclose($pipes[2]);
    // TODO: Write passphrase in pipes[3].
    fclose($pipes[3]);
    // Close all pipes before proc_close!
    $code = proc_close($process);
    return array($output, $error, $code);
}
$cmd1 = 'set XXX=/xxx/xxx/xxx';
$cmd2 = 'set XXX';
echo var_export(executeCommand($cmd1), 1), "\n";
var_export(executeCommand($cmd2));
x
array (
  0 => '',
  1 => '',
  2 => 0,
)
array (
  0 => '',
  1 => 'Environment variable XXX not defined
',
  2 => 1,
)

$cmd1 = 'set XXX=/xxx/xxx/xxx & set XXX';
echo var_export(executeCommand($cmd1), 1), "\n";
 
x
array (
  0 => 'XXX=/xxx/xxx/xxx
',
  1 => '',
  2 => 0,
)