Can't install libgtk-3-dev for MX Linux MX-19.4_x64

[simwin]

Now I just did a test and installed a ton of Nvidia packages from the MX Test Repo using MXPI (because I don't have Nvidia hardware and can't use the Nvidia Drive Installer).
Nothing I installed or updated libglvnd0, libglvnd-core-dev, or libglvnd-dev, so I don't know how you got those.

Try this:
1. Install MX-19.4
2. Don't install libgtk-3-dev and don't make update
3. Install newest NVIDIA 455.45.01

OR

1. Install MX-19.4
2. Make update and don't install libgtk-3-dev
3. Install newest NVIDIA 455.45.01

[simwin]

That is what I am saying, you need to force libglvnd-dev to 1.1.0-1 and then reinstall everything that is removed, but make sure your install them from the Stable repo.

It would be easy to reinstall all system because I don't know the names of all installed testing libs. And Yes - Timeshift is a good idea to use. Thank you for your help! It was very valuable to me!

[SwampRabbit]

Now I just did a test and installed a ton of Nvidia packages from the MX Test Repo using MXPI (because I don't have Nvidia hardware and can't use the Nvidia Drive Installer).
Nothing I installed or updated libglvnd0, libglvnd-core-dev, or libglvnd-dev, so I don't know how you got those.

Try this:
1. Install MX-19.4
2. Don't install libgtk-3-dev and don't make update
3. Install newest NVIDIA 455.45.01

OR

1. Install MX-19.4
2. Make update and don't install libgtk-3-dev
3. Install newest NVIDIA 455.45.01

I stated I did this essentially, but the difference is the part I made bold above, I can't verify with the actual Nvidia Driver Installer because I don't have Nvidia hardware, the installer stops as soon as it checks this.

Again, when I manually installed Nvidia drivers from the MX Test Repo (using MXPI) it did not pull in libglvnd0, libglvnd-core-dev, or libglvnd-dev. libgtk-3-dev and the rest should install fine from the MX Stable repo if using the Nvidia drivers from the MX Test Repo.

I just verified that by again:
1) fully updated MX-19.4
2) manually installed Nvidia drivers, Nvidia Settings, nvidia-smi, and a few other things from the MX Test Repo (using MXPI) it did not pull in libglvnd0, libglvnd-core-dev, or libglvnd-dev
3) installed libglvnd0, libglvnd-core-dev, or libglvnd-dev from the Stable repo (using MXPI)
4) installed libgtk-3-dev from the Stable repo (using MXPI)

The only thing different is for #2 I didn't use the Nvidia Driver Installer (because I can't). So the only way to know if that is an issue is someone else try the same thing but use the Nvidia Driver Installer for step 2.
BUT... I don't think (90%) that is the issue either. I think you somehow got packages you shouldn't have from the MX Test Repo which caused the conflict with libgtk-3-dev. It doesn't really matter now and honestly I can't spend time testing every combination under the sun anymore... we have other MX things to do... and I have a full time job. Sorry, hopefully your reinstall will go better.

[simwin]

It doesn't really matter now and honestly I can't spend time testing every combination under the sun anymore... we have other MX things to do... and I have a full time job. Sorry, hopefully your reinstall will go better.

OK, ok... I understand it. You are right... Many thanks for your help and for your time spent trying to understand this issue!!!