mysql_upgrade not found

I’ve just upgrade my system, but Mysql don’t start:

120319 15:20:39 [Note] Plugin 'FEDERATED' is disabled.
mysqld: Table 'mysql.plugin' doesn't exist
120319 15:20:39 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
120319 15:20:39  InnoDB: Initializing buffer pool, size = 8.0M
120319 15:20:39  InnoDB: Completed initialization of buffer pool
120319 15:20:39  InnoDB: Started; log sequence number 0 43665
120319 15:20:39 [ERROR] Can't start server : Bind on unix socket: No such file or directory
120319 15:20:39 [ERROR] Do you already have another mysqld server running on socket: /var/run/mysqld/mysqld.sock ?
120319 15:20:39 [ERROR] Aborting

so I am asked to run myslq_upgrade, but it’s not present on the system…

Any help?

Answer

Finally, I had to manually remove some of the package, rename old database and configuration file, reinstall things and it worked, but still no mysql_upgrade….

Anyway, thanks for the help