I encountered the same bug as OP on a freshly installed Debian 13.6. I downloaded mysqltuner_2.9.2-1_all.deb from the link in this bug and installed it. The error was gone and mysqltuner worked as expected.
I encountered the same bug as OP on a freshly installed Debian 13.6. I downloaded mysqltuner_2.9.2-1_all.deb from the link in this bug and installed it. The error was gone and mysqltuner worked as expected.