How to resolve "input file specifed" error when using phpmyadmin with php-fpm in a chroot environment?

Question

PHP

Good afternoon.

php7fpm + nginx via socket.

the php config is standard, the pool config too, the chroot is configured in the site folder and is designated as - /
the index.php of the site itself is running normally. getcwd() returns - /

current nginx config -

....
root /var/www;
location /pma
        {
                alias /var/www/phpmyadmin; #/usr/share/phpnyadmin тоже использовался#

                location ~ \.php$
                {
                        include fastcgi_params;
                        fastcgi_pass unix:/run/php/php7.0-fpm.sock;
                        fastcgi_index index.php;
                        fastcgi_param SCRIPT_FILENAME $request_filename;
                       #так же были использованны - 
                       #fastcgi_param SCRIPT_FILENAME /phpMyAdmin/$1;
                       #fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                       #fastcgi_param DOCUMENT_ROOT /var/www/phpMyAdmin/;

}

                location ~* \.(js|css|png|jpg|jpeg|gif|ico)$
                {
                        access_log off;
                        log_not_found off;
                        expires 1d;
                }
        }
....

Before that, I forwarded a soft link to /usr/share/phpmyadmin (to chroot/phpmyadmin ), but it didn't work. The output of the regular function scandir( "/phpmyadmin" ) from php was - false.
Then I did the same only using mount --bind. The output of scandir is now standard. Permissions on the chroot/phpmyadmin folder are the same as php-fpm.

i'm at a loss, output " php phpmyadmin/index.php " from chroot/ folder

PHP Warning:  require_once(./libraries/String.class.php): failed to open stream: No such file or directory in /var/www/phpmyadmin/libraries/common.inc.php on line 58
PHP Fatal error:  require_once(): Failed opening required './libraries/String.class.php' (include_path='.:/usr/share/php') in /var/www/phpmyadmin/libraries/common.inc.php on line 58

as I understand it, it launches it, but can no longer connect something else because of the chroot.

nginx log output per request

2017/05/13 18:42:21 [error] 1516#1516: *3 FastCGI sent in stderr: "Unable to open primary script: /var/www/phpmyadmin/index.php (No such file or directory)" while reading response header from upstream, client: xxx.xxx.xxx.xxx, server: localhost, request: "GET /pma/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php7.0-fpm.sock:", host: "anyhost"

In general, it may be necessary to somehow configure everything differently when chrooting? without it - everything is ok.
Just do not suggest, please, to create a separate pool without chroot for phpmyadmin.

Thank you.