Libtables configuration
$lt_settings global variable
error_rewrite array
This is an associative array of possible database error messages (as the key) and the user-friendly text to show instead (as the value). The key can either be a plain string (to be matched literally against the error message) or be a regular expression. The latter should start and end with a slash as is usual in PHP. When using a regular expression, replacement patterns like $1, $2 can be used in the user-friendly text to be replaced with the matches from the regular expression.
Example:
'error_rewrite' => [
'Database connection failed' => 'The database is currently unavailable; please try again later',
"/.*Duplicate entry '(.*)' for key 'username_unique'/" => 'Username "$1" is already present in the database'
]