I was fixing an issue in Magento and I found a suggestion to run
composer update
and
setup:upgrade
After this I fell in an error for wrong log file path:
/var/www/html//var/log/system.log
I found this error in var/log/exception.log
The stream or file "/var/www/html//var/log/system.log" could not be opened:
failed to open stream: Permission denied {"exception":"[object]
(UnexpectedValueException(code: 0): The stream or file
\"/var/www/html//var/log/system.log\" could not be opened: failed to open
stream: Permission denied at
/var/www/html/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php:107)"
} []