[physfs] Build error on x64-windows. Compatibility with CMake < 3.5 has been removed from CMake.

[NooneAtAll3-2]

I apologize if this isn't issue in vcpkg, but I don't have much experience in builds and am very very confused...

Our builds are failing, but only on windows. And despite specifying "~3.31.0" as cmake version to install and having cmake_minimum_required (VERSION 3.25...3.29) in CMakeLists.txt, we get Compatibility with CMake < 3.5 has been removed from CMake. error

After staring at the logs, I think they are saying that when vcpkg is building physfs, it is calling C:/Program Files/Microsoft Visual Studio/18/Enterprise/Common7/IDE/CommonExtensions/Microsoft/CMake/CMake/bin/cmake.exe - cmake that comes with VS compiler in github's windows image(?) - instead of newly installed/updated cmake that is specified in PATH.

But I don't understand what causes that - whether it's lukka/run-cmake deciding "windows build must use VS CMake", ninja looking at its own insides, vcpkg listing hardcoding something or error in https://github.com/icculus/physfs it downloads from

Again, I sincerely apologize if it's not an issue on your side, but I'm very confused and need some help

[autoantwort]

The cmake version from VS is probably too new for the port you are trying to build. You could try running vcpkg with the param --x-abi-tools-use-exact-versions which forces vcpkg to use a cmake version that is older an known to work.
Add set(VCPKG_INSTALL_OPTIONS "--x-abi-tools-use-exact-versions") to your cmake project before the first project call.

[dg0yt]

Call Stack (most recent call first):
 D:/a/_temp/60786817/cmake-3.31.12-windows-x86_64/share/cmake-3.31/Modules/CMakeDetermineSystem.cmake:146 (include)

Switch to CMake >= 4.0.

The current HEAD of vcpkg chooses (downloads) at least CMake 4.3.3. This is tested in CI. And vcpkg passes a CMake setting which mitigates the minimum version issue:

vcpkg/scripts/ports.cmake

Lines 6 to 8 in a0b1c8d

	if(CMAKE_VERSION VERSION_GREATER_EQUAL "4.0")
	set(ENV{CMAKE_POLICY_VERSION_MINIMUM} 3.5)
	endif()

i.e. this needs CMake 4.0. Cf. https://cmake.org/cmake/help/latest/release/4.0.html#variables

The CMAKE_POLICY_VERSION_MINIMUM variable was added to help packagers and end users try to configure existing projects that have not been updated to work with supported CMake versions. The CMAKE_POLICY_VERSION_MINIMUM environment variable was added to initialize it.

(I noticed that this variable is also reported in your CI log.)

[NooneAtAll3-2]

@dg0yt you're contradicting yourself. If vcpkg installs and uses its own cmake - then it doesn't matter what cmake our build system installs.

And apparently that error isn't caused by running old CMake (it's a really bad error string) - that error is caused by modern CMake trying to run script for old CMake

Just for you I changed the installed CMake to 4.3 - and I still get the same error

Something somewhere eats the full path to the file, but I think error points to CMakeLists.txt:14 (cmake_minimum_required) which corresponds to physfs' CMakeLists.txt, not our's

Physfs changed that line 3 years ago, how do I check what commit vcpkg is trying to download and build?

[dg0yt]

@dg0yt you're contradicting yourself.

I'm trying to help investigating an unexpected problem, in my free time. This morning I see two issues with this unexpected behavior. I reported the line in the call stack which shouldn't be there IMO.

Do you want me to continue, or shall I move on?

[dg0yt]

FTR https://github.com/raceintospace/raceintospace and raceintospace/raceintospace#1179 still point to vcpkg @ ea2a964 from April 1, 2025. It is older than the ENV{CMAKE_POLICY_VERSION_MINIMUM} solution in a1aebfa from April 2, 2025.

So the updated advise is: Update your vcpkg reference. You may still chose old version of ports via manifest.