This test does not work on Windows, if the child process has OPcache
enabled via php.ini, since TEMP is not set in the environment, so
OPcache can't find the base address file, and terminates the childs.
To avoid this (and potentially some other issues regarding missing
environment variables, such as PATH), we force the child process to
ignore any ini files.
putenv('ENV_1=ENV_1');
$env = ['ENV_2' => 'ENV_2'];
-$cmd = [$php, '-r', 'var_dump(getenv("ENV_1"), getenv("ENV_2"));'];
+$cmd = [$php, '-n', '-r', 'var_dump(getenv("ENV_1"), getenv("ENV_2"));'];
echo "\nEnvironment inheritance:\n";
$proc = proc_open($cmd, $ds, $pipes);