There is a server error 502 when writing to the sqlite3 database on php 7 fpm, but nothing in the php logs. Why nothing?

Question

PHP

nginx + php7-fpm. Gives an error 502. The php logs are clean (in php.ini is set to E_ALL).
In the old manner, using the die method, I determined that the error between and Base is sqlite3. Foreign keys are used. As I understand it, replace also affects id, which is a foreign key - and this is the cause of the error, and update should be used without touching id. OK. But why is there nothing in the PHP logs? And why even try catch finally around execute didn't help and nginx stubbornly issues 502?
$query = $pdo->prepare('REPLACE INTO ...');
$query->execute([...]);

Answer 1

Look in both logs
/var/log/php-fpm/error.log
/var/log/php-fpm/www-error.log
And also check that there are paths to the
sudo vi log file in the configs /etc/php-fpm .conf
error_log = /var/log/php-fpm/error.log
and
sudo vi /etc/php-fpm.d/www.conf
php_admin_value[error_log] = /var/log/php-fpm/www-error.log
If there is a problem with permissions, then in /etc/php-fpm.d/www.conf check
user =
group =
by default, apache is here