Peter's questions

After installing VLC player on Ubuntu 24.04.1 LTS. I cannot use it.

The following error appears:

user@lh:~$ vlc
Driver does not support the 0x4680 PCI ID.
libGL error: failed to create dri screen
libGL error: failed to load driver: iris
VLC media player 3.0.20 Vetinari (revision 3.0.20-1-g2617de71b6)
[00005ce65b1d6a00] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
Qt: Session management error: Could not open network socket
Fontconfig warning: FcPattern object weight does not accept value [0 205)
Segmentation fault (core dumped)

I deinstalled gcc5.5 and deleted the corresponding ppa:ubuntu-toolchain-r/test.

Then, I added the ppa for gcc-5.4:

sudo add-apt-repository ppa:jonathonf/gcc-5.4
sudo apt-get update

Afterwards I tried to install it with

sudo apt install gcc-5

... and get the following error message:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 gcc-5 : Depends: cpp-5 (= 5.4.1-12ubuntu4~16.04.york0) but 5.5.0-12ubuntu1~16.04 is to be installed
         Depends: gcc-5-base (= 5.4.1-12ubuntu4~16.04.york0) but 5.5.0-12ubuntu1~16.04 is to be installed
         Depends: libgcc-5-dev (= 5.4.1-12ubuntu4~16.04.york0) but 5.5.0-12ubuntu1~16.04 is to be installed
E: Unable to correct problems, you have held broken packages.

I tried a lot like:

sudo apt-get install -f
sudo apt autoremove

The apt-cache policy says:

sudo apt-cache policy gcc
gcc:
  Installed: (none)
  Candidate: (none)
  Version table: