Comment 22 for bug 1845281

@eddgrant Sorry, I rushed my previous comment a bit. I'll elaborate below.

To start with the good news: upgrading libmutter to the proposed version has fixed the IntelliJ crash problem. I haven't had any trouble since.

I was referring to the article https://wiki.ubuntu.com/Testing/EnableProposed, referenced by @sil2100 in #10. It first instructs you how to enable proposed updates, and then, in the paragraph "Selective upgrading from proposed", to pin packages to their current versions (i.e. stable, not proposed), by creating `/etc/apt/preferences.d/proposed-updates` with this content:

```
Package: *
Pin: release a=eoan-proposed
Pin-Priority: 400
```

The article reads `xenial`, not `eoan`, but I'm assuming you made that substitution, because we're dealing with Ubuntu 19.10 here, not 18.04.

If you did all this, then that would prevent `apt upgrade` from upgrading ALL packages from `eoan-proposed`. That's good, because we're only interested in testing the fix for `mutter`, not the hundreds of other proposed packages. However, if you then continue to follow instructions from that same page, you would end up doing something like:

`sudo apt-get install mutter/eoan-proposed`

This won't work as intended, because the new version of mutter depends on new versions of some other stuff (like libmutter, probably), also in eoan-proposed, but apt won't see it because it has been pinned by the pin file you created. The proper way of going about this, then, is to:

- comment the contents of the `/etc/apt/preferences.d/proposed-updates` with #'s
- run `sudo apt-get install libmutter-5-0/eoan-proposed mutter/eoan-proposed`
- uncomment again, to make sure you won't cut yourself on the bleeding edge of some other update

Good luck!