Update cmake_policy in vcpkg

[gwankyun]

Compatibility with versions of CMake older than 3.10 is deprecated.

[BillyONeal]

/azp run

[BillyONeal]

Rerunning due to network mistake last night.

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[BillyONeal]

I think this should be set to 3.16.3
Related: microsoft/vcpkg-docs#415

Tagging vcpkg-team-review to confirm with other maintainers.

[dg0yt]

I think this should be set to 3.16.3

Do you want to raise the general minimum CMake version (as avaiable in Ubuntu 20.04)?
(Just asking.)

[BillyONeal]

Do you want to raise the general minimum CMake version (as avaiable in Ubuntu 20.04)?
(Just asking.)

That's what I'm arguing, yes. The reason we cared about old CMake versions is "work with the CMake the downstream customer is likely to be using on our supported Linuxes", so with Debian 10 "Buster" leaving support the new oldest distro we care about is Ubuntu 20.04.

[dg0yt]

This is what I concluded from the discussion.
BTW it is not necessary to resync with master all the time.

[BillyONeal]

@vicroms @ras0219-msft and I discussed this today and affirm that we want this to say 3.16.

[silverqx]

Can we merge this? The output is really flooded with these warnings, it's hard to develop with them.

Ubuntu 20.04 LTS has this CMake version, there is no need to support versions before v3.16 as no other distro uses a lower version of CMake.

[dg0yt]

There is a change requested but not applied yet.

And there is a set of PRs which all trigger world rebuilds, so it might make sense to coordinate them to reduce impact on users.

• [vcpkg] Set CMP0174 NEW #42045 (ready)
• [vcpkg script]WIP: ninja 1.12 (Reprise from #39260) #41980 (not yet ready)

[silverqx]

Ok thats reasonable, but what about cherrypick this change only to main? It's not a big deal if not, we will have flooded output for a while.

So I patched it manually/locally, to get rid of these warnings, I'm not arguing anymore, sry 😁

[dg0yt]

It is not causing errors, and there is a mitigation: CMake 3.30.

Again, this PR causes a world rebuild for all users: It invalidates all binary artifacts. That's why it shouldn't occur too often. (And that's the reason why I don't simply open or change another PR. It takes two days to pass CI.)

Ping @gwankyun

[patrikhuber]

Looking forward to getting this merged, I just ran a sudo apt update/upgrade on my WSL Ubuntu 24.04, that seemed to have updated CMake to 3.31, and the terminal is now flooded with those warnings, it's hard to find/see anything else.

[gwankyun]

It is not causing errors, and there is a mitigation: CMake 3.30.

Again, this PR causes a world rebuild for all users: It invalidates all binary artifacts. That's why it shouldn't occur too often. (And that's the reason why I don't simply open or change another PR. It takes two days to pass CI.)

Ping @gwankyun

OK, I'm not familiar with the PR process.

[dg0yt]

OK, I'm not familiar with the PR process.

If I understand correctly, #41574 (comment) says that my suggestions in #41574 (review) should be applied. You can do this right here on this page.

If you want somebody else to continue, it is also okay. Just leave a note.

[dg0yt]

LGTM if the only failing port is cmake-user.

cmake-user is a test port, located in scripts/test_ports. It tests standard find_package for the current vcpkg cmake (3.30) and for the minimum supported version. That's why it fails: It still tests with 3.7 binaries, but the toolchain wants 3.16 now.

So this port needs to be updated, too. Either you do it in this PR, or I do it separately. But I don't know if I will have the time to do so before sunday.

[dg0yt]

For a minimal fix, you only have to remove cmake 3.7 testing from cmake-user's default features, i.e. these lines:

vcpkg/scripts/test_ports/cmake-user/vcpkg.json

Lines 21 to 27 in 9b5cb8e

	},
	{
	"name": "cmake-user",
	"default-features": false,
	"features": [
	"cmake-3-7"
	],

This keeps testing with cmake 3.30 while disabling the outdated part.
I can complete remove cmake-3-7 and add cmake-3-16 in a separate PR.

[gwankyun]

@microsoft-github-policy-service agree

[Osyotr]

There are a few other things (mostly comments) that can be removed after rasing minimum CMake version to 3.16.

vcpkg/scripts/buildsystems/vcpkg.cmake

Lines 4 to 5 in b2cb0da

	# NOTE: to figure out what cmake versions are required for different things,
	# grep for `CMake 3`. All version requirement comments should follow that format.

Not sure it's worth restting CI over this.

[BillyONeal]

I fixed the 3-7 test rather than deactivating it.

[BillyONeal]

I'm reverting the cmake-user changes because we merged #42203