Dear Maintainer,

before yesterday both my kmail and korganizer worked as aspected.

This morning after the boot they warn me "A required background service is
not running. This application cannot be used without it."

So I have executed

~ <bash> $ akonadictl restart
org.kde.pim.akonadictl: Starting Akonadi Server...
Error: akonadi_control was started but didn't register at D-Bus session bus.
Make sure your system is set up correctly!

~ <bash> $ Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
org.kde.pim.akonadiserver: Starting up the Akonadi Server...
akonadi.collectionattributetable                   OK
akonadi.collectionmimetyperelation                 OK
akonadi.collectionpimitemrelation                  OK
akonadi.collectiontable                            OK
akonadi.flagtable                                  OK
akonadi.mimetypetable                              OK
akonadi.parttable                                  OK
akonadi.parttypetable                              OK
akonadi.pimitemflagrelation                        OK
akonadi.pimitemtable                               OK
akonadi.pimitemtagrelation                         OK
akonadi.resourcetable                              OK
akonadi.schemaversiontable                         OK
akonadi.tagattributetable                          OK
akonadi.tagremoteidresourcerelationtable           OK
akonadi.tagtable                                   OK
akonadi.tagtypetable                               OK
FATAL ERROR: Can't execute '/usr/bin/mariadb'
org.kde.pim.akonadiserver: Running DB initializer
org.kde.pim.akonadiserver: DB initializer done
org.kde.pim.akonadiserver: DATABASE ERROR:
org.kde.pim.akonadiserver:   Error code: "2013"
org.kde.pim.akonadiserver:   DB error:  "Lost connection to server during query"
org.kde.pim.akonadiserver:   Error text: "Lost connection to server during query QMYSQL: Unable to execute statement"
org.kde.pim.akonadiserver:   Values: QList(QVariant(QString, "akonadi"), QVariant(QString, "SchemaVersionTable"))
org.kde.pim.akonadiserver:   Query: "SELECT information_schema.REFERENTIAL_CONSTRAINTS.CONSTRAINT_NAME, information_schema.KEY_COLUMN_USAGE.COLUMN_NAME, information_schema.KEY_COLUMN_USAGE.REFERENCED_TABLE_NAME, information_schema.KEY_COLUMN_USAGE.REFERENCED_COLUMN_NAME, information_schema.REFERENTIAL_CONSTRAINTS.UPDATE_RULE, information_schema.REFERENTIAL_CONSTRAINTS.DELETE_RULE FROM information_schema.REFERENTIAL_CONSTRAINTS INNER JOIN information_schema.KEY_COLUMN_USAGE ON ( information_schema.REFERENTIAL_CONSTRAINTS.CONSTRAINT_NAME = information_schema.KEY_COLUMN_USAGE.CONSTRAINT_NAME ) WHERE ( information_schema.KEY_COLUMN_USAGE.TABLE_SCHEMA = :0 AND information_schema.KEY_COLUMN_USAGE.TABLE_NAME = :1 )"
qt.sql.mysql: QMYSQLResult::cleanup: unable to free statement handle
org.kde.pim.akonadiserver: DATABASE ERROR while PREPARING QUERY:
org.kde.pim.akonadiserver:   Error code: "2006"
org.kde.pim.akonadiserver:   DB error:  "Server has gone away"
org.kde.pim.akonadiserver:   Error text: "Server has gone away QMYSQL: Unable to prepare statement"
org.kde.pim.akonadiserver:   Query: "SELECT information_schema.REFERENTIAL_CONSTRAINTS.CONSTRAINT_NAME, information_schema.KEY_COLUMN_USAGE.COLUMN_NAME, information_schema.KEY_COLUMN_USAGE.REFERENCED_TABLE_NAME, information_schema.KEY_COLUMN_USAGE.REFERENCED_COLUMN_NAME, information_schema.REFERENTIAL_CONSTRAINTS.UPDATE_RULE, information_schema.REFERENTIAL_CONSTRAINTS.DELETE_RULE FROM information_schema.REFERENTIAL_CONSTRAINTS INNER JOIN information_schema.KEY_COLUMN_USAGE ON ( information_schema.REFERENTIAL_CONSTRAINTS.CONSTRAINT_NAME = information_schema.KEY_COLUMN_USAGE.CONSTRAINT_NAME ) WHERE ( information_schema.KEY_COLUMN_USAGE.TABLE_SCHEMA = :0 AND information_schema.KEY_COLUMN_USAGE.TABLE_NAME = :1 )"
org.kde.pim.akonadiserver: DATABASE ERROR while PREPARING QUERY:
org.kde.pim.akonadiserver:   Error code: "2006"
org.kde.pim.akonadiserver:   DB error:  "Server has gone away"
org.kde.pim.akonadiserver:   Error text: "Server has gone away QMYSQL: Unable to prepare statement"
org.kde.pim.akonadiserver:   Query: "SELECT information_schema.REFERENTIAL_CONSTRAINTS.CONSTRAINT_NAME, information_schema.KEY_COLUMN_USAGE.COLUMN_NAME, information_schema.KEY_COLUMN_USAGE.REFERENCED_TABLE_NAME, information_schema.KEY_COLUMN_USAGE.REFERENCED_COLUMN_NAME, information_schema.REFERENTIAL_CONSTRAINTS.UPDATE_RULE, information_schema.REFERENTIAL_CONSTRAINTS.DELETE_RULE FROM information_schema.REFERENTIAL_CONSTRAINTS INNER JOIN information_schema.KEY_COLUMN_USAGE ON ( information_schema.REFERENTIAL_CONSTRAINTS.CONSTRAINT_NAME = information_schema.KEY_COLUMN_USAGE.CONSTRAINT_NAME ) WHERE ( information_schema.KEY_COLUMN_USAGE.TABLE_SCHEMA = :0 AND information_schema.KEY_COLUMN_USAGE.TABLE_NAME = :1 )"
terminate called after throwing an instance of 'Akonadi::Server::DbException'
  what():  Failed to query index
Sql error: Server has gone away QMYSQL: Unable to execute query
Query: SHOW INDEXES FROM CollectionTable WHERE `Key_name` = 'CollectionTable_parentAndNameIndex'
Failed to open metadata file: Permesso negato
KCrash: Application 'akonadiserver' crashing... crashRecursionCounter = 2


The only packages that have relevance from yesterday upgrade are mariadb
and kdepim-runtime.

Cheking the downgrade of both or one at the time the result is an
incompatibility of the versions of kdepim-runtime (4:25.12.1-3 and
4:25.12.1-2) with last mariadb (1:11.8.6-1).

With mariadb 1:11.8.5-4 akonadi starts.

Thanks

Stefano