cmake_minimum_required() uses "...", which is a feature available in 3.12 onward leading to broken configuration

[aleksandaratanasov]

I did this

Added curl as a submodule to my project to use as a dependency. No changes have been done to the contents of the master branch.

Using Visual Studio 2017 I ran (from the CMake menu) the cache generation.

I expected the following

Properly configured curl as a dependency.

Instead I received an error regarding the version and that it is either too short or too long. I checked CMakeLists.txt and found cmake_minimum_required(VERSION 3.2...3.16 FATAL_ERROR). Based on the official CMake documentation the use of ... to specify a policy range (in this case between 3.2 and 3.16) this feature has been introduced in 3.12.

Solution

Either remove the ... and check if curl can actually still be configured with as low as CMake 3.2 or increase the minimum to 3.12. Note that at least on my machine VS2017 is shipped with 3.11. Older versions of VS will have even bigger issues and upgrading CMake that is shipped as an extension for the IDE is non-existent and one needs to wait for the VS team at Microsoft to ship one.

curl/libcurl version

Latest from master branch.

operating system

Windows 10 Pro 64bit

[aleksandaratanasov]

Just as a test I removed the cmake_minimum_required() from the project. Following configuration and build step in VS2017 didn't exhibit any issues whatsoever.

[jzakrzewski]

From the link you've posted:

If the running version of CMake is older than 3.12, the extra ... dots will be seen as version component separators, resulting in the ... part being ignored and preserving the pre-3.12 behavior of basing policies on .

[bagder]

I second @jzakrzewski on this: the cmake documentation quite clearly says that this syntax works in older versions too.

[aleksandaratanasov]

Did you guys try the CMake shipped with Visual Studio? Please note that VS ships its own version, which (at least up to 2017 included) is impossible to be replaced by another one. I will check with a standard installation of CMake (have that too) and hopefully it will work (as you have said).

[jzakrzewski]

It's not CMake that throws errors but VS 2017 itself trying to analyse the version string.
See: CMake issue and VS Issue for reference.

[bagder]

This is clearly not our bug and not even a cmake bug, but a problem with Visual Studio. You also seem to have found an easy and simple work-around to get this working for you.

I do not think there's any action left for us to do here.