mysqld_pre_systemd fails when starting MySQL on Fedora I installed MySQL using dnf (I'm on fedora) and from the officials rpm on the website. Both had the same problem : I have an error when I do systemctl start mysqld.service.
So I checked systemctl status mysqld.service and got this :
● mysqld.service - MySQL Server
     Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
     Active: failed (Result: exit-code) since Wed 2021-04-07 17:07:54 CEST; 6s ago
       Docs: man:mysqld(8)
             http://dev.mysql.com/doc/refman/en/using-systemd.html
    Process: 39884 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
    Process: 39913 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS (code=exited, status=1/FAILURE)
   Main PID: 39913 (code=exited, status=1/FAILURE)
     Status: &quot;Data Dictionary upgrade from MySQL 5.7 in progress&quot;
        CPU: 734ms

avril 07 17:07:53 laptop-de-mathis systemd[1]: Starting MySQL Server...
avril 07 17:07:53 laptop-de-mathis mysqld_pre_systemd[39905]: No such file or directory
avril 07 17:07:53 laptop-de-mathis mysqld_pre_systemd[39906]: No such file or directory
avril 07 17:07:53 laptop-de-mathis python3[39907]: detected unhandled Python exception in '/usr/sbin/semanage'
avril 07 17:07:53 laptop-de-mathis mysqld_pre_systemd[39909]: No such file or directory
avril 07 17:07:53 laptop-de-mathis python3[39910]: detected unhandled Python exception in '/usr/sbin/semanage'
avril 07 17:07:53 laptop-de-mathis mysqld_pre_systemd[39912]: No such file or directory
avril 07 17:07:54 laptop-de-mathis systemd[1]: mysqld.service: Main process exited, code=exited, status=1/FAILURE
avril 07 17:07:54 laptop-de-mathis systemd[1]: mysqld.service: Failed with result 'exit-code'.
avril 07 17:07:54 laptop-de-mathis systemd[1]: Failed to start MySQL Server.

I don't really know what to do with this information. I also checked journalctl, but StackExchange considers it as spam, so I can't post it.
Does anyone have an idea how to get me out of this situation?
As mentioned in the comments, the /usr/sbin/semanage file was not working properly. After using the dnf provides command (dnf provides /usr/sbin/semanage), dnf told me that this file was from the policycoreutils-python-utils-3. 1-4.fc33.noarch, so I reinstalled it with dnf reinstall (dnf reinstall policycoreutils-python-utils-3.1-4.fc33.noarch), rebooted, and my problem was solved.
However, I ran into another problem, again in the same place, which I've listed here.