[discussion] Define a policy for raising our dependencies' versions

[Desour]

I'd like to be able to use C++17, and also C++20 when available, to have an easier life. And upgrading other libs and tools (like cmake) is also nice to have.

Our dependencies are listed here:
https://github.com/minetest/minetest/blob/master/doc/compiling/linux.md#dependencies
But it's nowhere defined based on what they are limited, or in other words, which distributions we want to support. This makes it unclear at what point we may raise the dependency versions.

Just an example how such a policy can look like:
https://opensource.google/documentation/policies/cplusplus-support

Suggestion for a policy:
Always support all ubuntu lts version that still have full ubuntu support.
Rationale: Ubuntu is rather conservative, so few people of other distros will see breakage.

Also relevant: The end of support for ubuntu 18.04 is/was this year, and github isn't even providing a runner for it anymore, so we're currently skipping our old gcc and clang ci builds (we could still use docker for older versions though):
https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners#supported-runners-and-hardware-resources
https://ubuntu.com/about/release-cycle
7bfea9b

Edit: See also https://irc.minetest.net/minetest-dev/2023-06-11#i_6090527.

[Zughy]

Just in case you missed it and you want to proceed with such proposal, you've received 2 thumbs up by 2 different core devs

[Desour]

I've seen that. I'm working on a draft. I just haven't finished it yet because doing this stuff is kinda boring, and there's no need to hurry.