Some updates required to work with cmake version 4

[dl1ycf]

Lately, homebrew has updated cmake to version 4 (on my system, version 4.0.1 is now installed).
This leads to the following error

==> Reinstalling pothosware/pothos/limesuite
==> cmake .. -DENABLE_QUICKTEST=OFF -DENABLE_OCTAVE=OFF -DDOWNLOAD_IMAGES=FALSE -DENABLE_STREAM=ON -DENABLE_GUI=ON -DENA
Last 15 lines from /Users/chwu/Library/Logs/Homebrew/limesuite/01.cmake:
-Wno-dev
-DBUILD_TESTING=OFF
-DCMAKE_OSX_SYSROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk

CMake Error at CMakeLists.txt:4 (cmake_minimum_required):
Compatibility with CMake < 3.5 has been removed from CMake.

Update the VERSION argument value. Or, use the ... syntax
to tell CMake that the project requires at least but has been updated
to work with policies introduced by or earlier.

Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.

---

perhaps "cmake_minimum_required" should be adjusted in CMakeListe.txt?

[altosz]

Same problem on 14.6.1

[klimchuk]

Same problem on macOS 15.5

[HughAndersonNUS]

Same here on my M2, MacOS 15.5. Does anyone have a workaround?
Cheers Hugh

[dl1ycf]

The is a workaround, but you have to edit one of the „internal“
homebrew files, and this update will then be lost each time you
update the homebrew core.

Basically, you have to add

-DCMAKE_POLICY_VERSION_MINIMUM=3.5

to the std_cmake_args, the standard cmake arguments. To do so,
edit the file

/opt/homebrew/Library/Homebrew/extend/os/mac/formula.rb

and locate the following:

    # Avoid false positives for clock_gettime support on 10.11.
    # CMake cache entries for other weak symbols may be added here as needed.
    args << "-DHAVE_CLOCK_GETTIME:INTERNAL=0" if MacOS.version == "10.11" && MacOS::Xcode.version >= "8.0"

    # Ensure CMake is using the same SDK we are using.
    args << "-DCMAKE_OSX_SYSROOT=#{MacOS.sdk_for_formula(self).path}" if MacOS.sdk_root_needed?
    args << "-DCMAKE_POLICY_VERSION_MINIMUM=3.5“

where I have added the last line.

While "brew reinstall <some_package> -" failed before this change, it succeeded after that. So one could equally blame homebrew rather than pothos for the incompatibility, but this is a matter of taste.