Building CMake fails on Darwin

[johannesring]

The following profile

extends:
- file: osx.yaml

packages:
  cmake:

fails with:

...
[cmake] -- The C compiler identification is Clang 5.1.0
[cmake] -- The CXX compiler identification is Clang 5.1.0
[cmake] CMake Error at Modules/Platform/Darwin.cmake:211 (message):
[cmake]   CMAKE_OSX_DEPLOYMENT_TARGET is '10.9' but CMAKE_OSX_SYSROOT:
[cmake] 
[cmake]    ""
[cmake] 
[cmake]   is not set to a MacOSX SDK with a recognized version.  Either set
[cmake]   CMAKE_OSX_SYSROOT to a valid SDK or set CMAKE_OSX_DEPLOYMENT_TARGET to
[cmake]   empty.
[cmake] Call Stack (most recent call first):
[cmake]   Modules/CMakeSystemSpecificInformation.cmake:36 (include)
[cmake]   CMakeLists.txt:14 (project)
[cmake] 
[cmake] 
[cmake] -- Configuring incomplete, errors occurred!
[cmake] See also "/Users/buildbot/.hashdist/tmp/cmake-ckvi5ak55y2k-1/CMakeFiles/CMakeOutput.log".
[cmake] ---------------------------------------------
[cmake] Error when bootstrapping CMake:
[cmake] Problem while running initial CMake
[cmake] ---------------------------------------------
[cmake] make: *** No targets specified and no makefile found.  Stop.
[cmake ERROR] Command '[u'/bin/bash', '_hashdist/build.sh']' returned non-zero exit status 2
[cmake ERROR] command failed (code=2); raising

[johannesring]

The MACOSX_DEPLOYMENT_TARGET in PROLOGUE is the problem. Unsetting it fixes the problem.

[ahmadia]

That is a valid environment value elsewhere. It is needed in a few places
to guarantee a specific build.

On Thursday, July 17, 2014, johannesring notifications@github.com wrote:

The MACOSX_DEPLOYMENT_TARGET in PROLOGUE is the problem. Unsetting it
fixes the problem.

—
Reply to this email directly or view it on GitHub
#368 (comment).

[johannesring]

Yes, but it makes cmake and cmake based packages fail. Can we unset the variable only for those packages?

[ahmadia]

This is a new error. I've built several packages with cmake on OS X and the
prologue. Is it possible that this is being caused by something else or a
new version of cmake?

On Thursday, July 17, 2014, johannesring notifications@github.com wrote:

Yes, but it makes cmake and cmake based packages fail. Can we unset the
variable only for those packages?

—
Reply to this email directly or view it on GitHub
#368 (comment).

[johannesring]

Googling suggests that this was introduced in cmake version 2.8.10. However, that version is from 2012 so I doubt you were using that. Did you use host-cmake?

[ahmadia]

I do, but I'm using cmake 2.8.12.2. Perhaps it's just building cmake that fails, let me check.

[johannesring]

Thanks! This profile file reproduces the problem for me:

extends:
- file: osx.yaml

packages:
  cmake:

[ahmadia]

It doesn't produce it for me. https://gist.github.com/ahmadia/7e7a38535db25e7172ef

@robertmaynard - any ideas? My inclination is to set the environment variable that cmake is asking for, instead of unsetting the deployment target.

[johannesring]

Thanks for testing. I see you have Xcode. I don't have that, only the command line tools. Therefore I cannot set CMAKE_OSX_SYSROOT to a valid SDK because I don't have one. I tried to do

export CMAKE_OSX_DEPLOYMENT_TARGET=""

but that didn't help.

[ahmadia]

Thanks, Apple. For now can you create a modified copy of osx.yaml file named osx_clt.yaml and have it explicitly not set the deployment target? I'd like to test that profile on some of our other tools before making any big switches.

[johannesring]

Yes, I will try that.

[robertmaynard]

Unfortunately CMAKE_OSX_DEPLOYMENT_TARGET and CMAKE_OSX_SYSROOT go hand in hand. As they combine together to become a form of cross compilation allowing you to build code for other versions of OSX.

I wonder if we can do detection to see if xcode is installed, since if that is the case we can determine that SDK's should exist. Otherwise we presume the person has used a custom built compiler or the standalone clt tools.

[ahmadia]

hmnn, so should we avoid setting OSX_DEPLOYMENT_TARGET when we don't have the command line tools installed?

[robertmaynard]

If you have XCode by itself without the command line tools you should be fine. IIRC we grab the compiler out of the SDK that was chosen and use that one.

[ahmadia]

Sorry, I meant when we don't have XCode installed. Thanks for clarifying, let me know if you have any better ideas on how to deal with this :)