set upper bound in cmake_minimum_required

[minrk]

setting an upper bound improves forward-compatibility as legacy version support is dropped. Without an upper bound, the minimum version is used as the policy version, which means that setting a version lower than 3.5 will result in warnings starting with cmake 3.27 and errors starting in 4.0 (release candidate out now). This change allows zeromq to build with cmake 4.

• 3.5 compat is deprecated in 3.27 (2023), removed in 4.0 (2025)
• 3.10 compat is deprecated in 3.31 (2024)

[myd7349]

This will fix configuration error with CMake 4.0.

[mcloughlan]

getting this issue when using fetchcontent in a cmake file with version 4 as minimum as well

[a4z]

found out too late that this pr exists, so I added #4789

which this pr would have already been merged, that would have spared me some time

[andoorve]

Hi, is there any blocker to this being merged?

[a4z]

Hi, is there any blocker to this being merged?

To me it seems, for some time, all PRs have failed.
For various reasons, either a specific specified clang version was not found that got updated in the base image, or new coverage versions introduce new warnings, which are triggered as errors, and/or simply flaky tests as it can happen in containers whith uncertain execution time

It's unfortunate, but nobody seems to investigate those topics, and I miss the time it would take to do that since my activity is atm not work releated :-(

[andoorve]

I see, it's indeed unfortunate. Looks like the last commit was 6 months ago.