Just updated a TW 64bit KDE and after rebooting I wanted to start Bleachbit, but it doesn’t come up. In the console I get:
~> bleachbit
scandir is not available, so falling back to slower os.walk()
(process:14934): Gdk-CRITICAL **: 09:58:17.415: gdk_screen_get_root_window: assertion 'GDK_IS_SCREEN (screen)' failed
That is not what he suggested you to do (he apparently assumed you understand how to use su).
He in fact asked you to do
su
after which you enter the root password and then do the statements “as root”.
And please read
man su
to understand why su says hat the user (xlock) does not exist.
BTW, to both you and @marel, I strongly advice to use
su -
instead of plain su. It is not as dangerous as it was earlier because they added code to avoid the worst, but it is still better (and also a good habit) to use the --login, or shortend to -l, or further shortend to - option.
When in KDE, you can also start Konsole as Superuser from the main menu. It includes su - usage.
