Catalina C++: Using headers yield error: no member named 'signbit' in the global namespace

Question

After upgrading to Catalina from Mojave, Setuping: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk in the env.

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Answer 1

@mkl 's solution helps to fix the similar issue on my side. Thanks.

Issue and solution on my side

I got the same issue to compile a project on basis of PCL. The solution is to set CommandLineTools SDK CMAKE_OSX_SYSROOT.

I tried @mkl's solution to do it in CMakeLists.txt, it doesn't work. So that I can only set it by cmake .. -DCMAKE_OSX_SYSROOT="/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk"

Another thing to mention: there are two versions of command line SDKs in my MacOS:

~ » /Library/Developer/CommandLineTools/SDKs/MacOSX
/Library/Developer/CommandLineTools/SDKs/MacOSX
MacOSX.sdk/       MacOSX10.14.sdk@

xcrun --show-sdk-path gives out the default one, but actually only MacOSX10.14.sdk works on my side.

Discussion of the similar issue in PCL's repo: https://github.com/PointCloudLibrary/pcl/issues/2601#issuecomment-621889211

Difference between SDKs

I don't know much about cmake and SDKs in c++. The difference I noticed in cmake building log from different SDKs as following:

/Library/Developer/CommandLineTools/SDKs/MacOSX:

-- Found OpenGL: /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework

/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk

-- Found OpenGL: /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/OpenGL.framework

On default:

-- Found OpenGL: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/OpenGL.framework

Seems like the issue happens on SDK choice for Opengl.

How to do it in CMakeLists.txt?

Appreciated it if anyone could advice.