When working with FFI under a PHP ZTS environment, there is no standard way to change the directory with libraries (dll/so/dylib/etc), so to get around this problem, you should use something like this polyfill:
<?php
$directory = 'path/to/libraries';
switch (\PHP_OS_FAMILY) {
case 'Windows':
\FFI::cdef('extern unsigned char SetDllDirectoryA(const char* lpPathName);', 'kernel32.dll')
->SetDllDirectoryA($directory)
;
break;
case 'Linux':
case 'BSD':
\FFI::cdef('int setenv(const char *name, const char *value, int overwrite);')
->setenv('LD_LIBRARY_PATH', $directory, 1)
;
break;
case 'Darwin':
\FFI::cdef('int setenv(const char *name, const char *value, int overwrite);')
->setenv('DYLD_LIBRARY_PATH', $directory, 1)
;
break;
}
?>