Error 500 - CLI.php - Use of undefined constant STDOUT

After some investigation I found that there are changes in system/Common.php for is_cli() method that cause current issue.

It's identified as CLI in condition:

PHP Code:

if (stristr(PHP_SAPI, 'cgi') && getenv('TERM')) 


because PHP_SAPI equals to fpm-fcgi and TERM variable equals to xterm.


Is this correct behavior? How this should be fixed?
(I am using docker with php-fpm and nginx.)