An attempt to upgrade MySQL failed with below error:
CONFIG_TEXT: Version check failed. Got the following error when calling the 'mysql' command line client
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
FATAL ERROR: Upgrade failed
Incorrect username is used.
To upgrade MySQL the following command should be used:
# MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql_upgrade -uadmin