[cmake-developers] the default value in CMake 3.5.2 for CMAKE_OSX_DEPLOYMENT_TARGET is too low for Xcode6

[James Burgess]

Hi Brad,
 Apologies, I didn’t look closely enough/didn’t understand that the discovery modules would be under influence of CMAKE_OSX_DEPLOYMENT_TARGET set from the CMakeFiles.txt, makes total sense now that you said that.

This is the doxygen project, I just did a git clone of their latest. Their CMakeLists.txt file is the problem, it has:

if (${CMAKE_SYSTEM} MATCHES "Darwin")
    set(CMAKE_CXX_FLAGS "-Wno-deprecated-register -mmacosx-version-min=10.5 ${CMAKE_CXX_FLAGS}")
    set(CMAKE_C_FLAGS "-Wno-deprecated-register -mmacosx-version-min=10.5 ${CMAKE_C_FLAGS}”)
    ...
endif()

If I'm going to put that in my CMakeList.txt then I don’t think CMake can really stop me from shooting myself in the foot.

Cheers,
- James



> On May 23, 2016, at 7:24 AM, Brad King <brad.king at kitware.com> wrote:
> 
> On 05/22/2016 01:27 AM, James Burgess wrote:
>> If you don’t set this you get 10.5. On any mac with Xcode 6 (7 is the latest)
> 
> CMake's default value for CMAKE_OSX_DEPLOYMENT_TARGET is empty, which results
> in either no -mmacosx-version-min flag being used or in the host OS X version,
> depending on the native build tool behavior for the selected generator.  Might
> this default be coming from project code?
> 
>> a CMake user will see strange problems if they use CMakeList.txt file that uses
>> a module like Threads or Iconv that compile c++ files as part of their discovery.
> 
> Please provide a complete CMakeLists.txt file and specify the command line
> of CMake you're using to produce this problem.
> 
> Thanks,
> -Brad
>