llvm dev - Oct 2016 - cmake 3.7.0-rc1 breaks stage2 bootstrap in openmp on 10.11 with Xcode 8

The new cmake 3.7.0-rc1 release produces a stage2 bootstrap failure in
openmp project build on OS X 10.11 under Xcode 8....

In file included from
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_alloc.c:16:
In file included from
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp.h:98:
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_lock.h:26:10:
fatal error: 'atomic' file not found
#include <atomic>
         ^

This appears to be due to the new cmake 3.7.0-rc1 resulting in
-isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
being used in the compilation of openmp....

cd /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
&& /sw/src/fink.build/llvm40-4.0.0-1/opt-bin/cc-st1-clang
-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
-Domp_EXPORTS
-I/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
-I/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
 -Wall -W -Wno-unused-parameter -Wwrite-strings
-Wmissing-field-initializers -pedantic -Wno-long-long
-Wcovered-switch-default -Wdelete-non-virtual-dtor -Werror=date-time
-O3 -DNDEBUG -arch x86_64 -arch i386 -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
-fPIC   -D _GNU_SOURCE -D _REENTRANT -I/sw/include -std=c++11
-fno-exceptions -Wno-sign-compare -Wno-unused-function
-Wno-unused-local-typedef -Wno-unused-value -Wno-unused-variable
-Wno-switch -Wno-covered-switch-default -Wno-deprecated-register
-Wno-gnu-anonymous-struct -Wno-unknown-pragmas
-Wno-missing-field-initializers -Wno-missing-braces -Wno-comment
-Wno-self-assign -Wno-vla-extension -Wno-format-pedantic -x c++ -o
CMakeFiles/omp.dir/kmp_alloc.c.o   -c
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_alloc.c

The problem doesn't exist under cmake 3.6.2 because the openmp build
doesn't append  -isysroot in that case.
              Jack
ps Note this seems to be related to using any SDK for -sysroot as
substituting...

-isysroot
/Volumes/Xcode/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk

from the Xcode 7.3.1 release also fails but substituting...

-isysroot /

or omitting -sysroot entirely allows the compilation to succeed. So it
seems that the openmp code doesn't like being compiled against SDKs
rather than / on darwin.

On Sat, Oct 8, 2016 at 1:33 PM, Jack Howarth
<howarth.mailing.lists at gmail.com> wrote:
> The new cmake 3.7.0-rc1 release produces a stage2 bootstrap failure in
> openmp project build on OS X 10.11 under Xcode 8....
>
> In file included from
>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_alloc.c:16:
> In file included from
>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp.h:98:
>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_lock.h:26:10:
> fatal error: 'atomic' file not found
> #include <atomic>
>          ^
>
Appending -v to see the header search paths emitted from the compiler
shows the following....

compiling without -sysroot (which is the behavior for cmake 3.6.2 and
earlier)....

clang -cc1 version 4.0.0 based upon LLVM 4.0.0 default target
x86_64-apple-darwin15.6.0
ignoring nonexistent directory
"/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../include/c++/v1"
ignoring nonexistent directory "/usr/local/include"
#include "..." search starts here:
#include <...> search starts here:
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
 /sw/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../lib/clang/4.0.0/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.

compiling with -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
as cmake 3.7.0-rc1 does...

lang -cc1 version 4.0.0 based upon LLVM 4.0.0 default target
x86_64-apple-darwin15.6.0
ignoring nonexistent directory
"/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../include/c++/v1"
ignoring nonexistent directory
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1"
ignoring nonexistent directory
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/local/include"
ignoring nonexistent directory
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/Library/Frameworks"
#include "..." search starts here:
#include <...> search starts here:
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
 /sw/include
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../lib/clang/4.0.0/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/System/Library/Frameworks
(framework directory)
End of search list.

compiling with -isysroot / instead....

clang -cc1 version 4.0.0 based upon LLVM 4.0.0 default target
x86_64-apple-darwin15.6.0
ignoring nonexistent directory
"/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../include/c++/v1"
ignoring nonexistent directory "/usr/local/include"
#include "..." search starts here:
#include <...> search starts here:
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
 /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
 /sw/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
 /sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../lib/clang/4.0.0/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.

So for both no usage of -sysroot or '-sysroot /', the search path of
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
is appended for the compiler but the case of  '-isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk',
the compiler attempts to use the non-existent search path of
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1.
> This appears to be due to the new cmake 3.7.0-rc1 resulting in
> -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
> being used in the compilation of openmp....
>
> cd
/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
> && /sw/src/fink.build/llvm40-4.0.0-1/opt-bin/cc-st1-clang
> -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
> -Domp_EXPORTS
-I/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
> -I/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
> -I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
>  -Wall -W -Wno-unused-parameter -Wwrite-strings
> -Wmissing-field-initializers -pedantic -Wno-long-long
> -Wcovered-switch-default -Wdelete-non-virtual-dtor -Werror=date-time
> -O3 -DNDEBUG -arch x86_64 -arch i386 -isysroot
>
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
> -fPIC   -D _GNU_SOURCE -D _REENTRANT -I/sw/include -std=c++11
> -fno-exceptions -Wno-sign-compare -Wno-unused-function
> -Wno-unused-local-typedef -Wno-unused-value -Wno-unused-variable
> -Wno-switch -Wno-covered-switch-default -Wno-deprecated-register
> -Wno-gnu-anonymous-struct -Wno-unknown-pragmas
> -Wno-missing-field-initializers -Wno-missing-braces -Wno-comment
> -Wno-self-assign -Wno-vla-extension -Wno-format-pedantic -x c++ -o
> CMakeFiles/omp.dir/kmp_alloc.c.o   -c
>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_alloc.c
>
> The problem doesn't exist under cmake 3.6.2 because the openmp build
> doesn't append  -isysroot in that case.
>               Jack
> ps Note this seems to be related to using any SDK for -sysroot as
> substituting...
>
> -isysroot
/Volumes/Xcode/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk
>
> from the Xcode 7.3.1 release also fails but substituting...
>
> -isysroot /
>
> or omitting -sysroot entirely allows the compilation to succeed. So it
> seems that the openmp code doesn't like being compiled against SDKs
> rather than / on darwin.

On Sat, Oct 8, 2016 at 2:08 PM, Jack Howarth
<howarth.mailing.lists at gmail.com> wrote:
> On Sat, Oct 8, 2016 at 1:33 PM, Jack Howarth
> <howarth.mailing.lists at gmail.com> wrote:
>> The new cmake 3.7.0-rc1 release produces a stage2 bootstrap failure in
>> openmp project build on OS X 10.11 under Xcode 8....
>>
>> In file included from
>>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_alloc.c:16:
>> In file included from
>>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp.h:98:
>>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_lock.h:26:10:
>> fatal error: 'atomic' file not found
>> #include <atomic>
>>          ^
>>
>
> Appending -v to see the header search paths emitted from the compiler
> shows the following....
>
> compiling without -sysroot (which is the behavior for cmake 3.6.2 and
> earlier)....
>
> clang -cc1 version 4.0.0 based upon LLVM 4.0.0 default target
> x86_64-apple-darwin15.6.0
> ignoring nonexistent directory
>
"/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../include/c++/v1"
> ignoring nonexistent directory "/usr/local/include"
> #include "..." search starts here:
> #include <...> search starts here:
>  /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
>  /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
>  /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
>  /sw/include
> 
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
> 
/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../lib/clang/4.0.0/include
>  /usr/include
>  /System/Library/Frameworks (framework directory)
>  /Library/Frameworks (framework directory)
> End of search list.
>
> compiling with -isysroot
>
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
> as cmake 3.7.0-rc1 does...
>
> lang -cc1 version 4.0.0 based upon LLVM 4.0.0 default target
> x86_64-apple-darwin15.6.0
> ignoring nonexistent directory
>
"/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../include/c++/v1"
> ignoring nonexistent directory
>
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1"
> ignoring nonexistent directory
>
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/local/include"
> ignoring nonexistent directory
>
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/Library/Frameworks"
> #include "..." search starts here:
> #include <...> search starts here:
>  /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
>  /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
>  /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
>  /sw/include
> 
/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../lib/clang/4.0.0/include
> 
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include
> 
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/System/Library/Frameworks
> (framework directory)
> End of search list.
>
> compiling with -isysroot / instead....
>
> clang -cc1 version 4.0.0 based upon LLVM 4.0.0 default target
> x86_64-apple-darwin15.6.0
> ignoring nonexistent directory
>
"/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../include/c++/v1"
> ignoring nonexistent directory "/usr/local/include"
> #include "..." search starts here:
> #include <...> search starts here:
>  /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
>  /sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
>  /sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
> 
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
>  /sw/include
> 
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
> 
/sw/src/fink.build/llvm40-4.0.0-1/build/stage1/bin/../lib/clang/4.0.0/include
>  /usr/include
>  /System/Library/Frameworks (framework directory)
>  /Library/Frameworks (framework directory)
> End of search list.
>
> So for both no usage of -sysroot or '-sysroot /', the search path
of
>
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
> is appended for the compiler but the case of  '-isysroot
>
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk',
> the compiler attempts to use the non-existent search path of
>
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1.
>
This issue seems to be specific to the llvm.org clang compiler. Using....

clang-4.0  -std=c++11  -x c++ --sysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
test.c -v

produces the bad search path of

ignoring nonexistent directory
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1"

whereas for the Apple clang 8.0 compiler, the same compilation
produces the valid search path of...

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1


>> This appears to be due to the new cmake 3.7.0-rc1 resulting in
>> -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
>> being used in the compilation of openmp....
>>
>> cd
/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
>> && /sw/src/fink.build/llvm40-4.0.0-1/opt-bin/cc-st1-clang
>> -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
>> -Domp_EXPORTS
-I/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/projects/openmp/runtime/src
>>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src
>> -I/sw/src/fink.build/llvm40-4.0.0-1/build/stage2/include
>> -I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/include
>>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/i18n
>>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/include/45
>>
-I/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/thirdparty/ittnotify
>>  -Wall -W -Wno-unused-parameter -Wwrite-strings
>> -Wmissing-field-initializers -pedantic -Wno-long-long
>> -Wcovered-switch-default -Wdelete-non-virtual-dtor -Werror=date-time
>> -O3 -DNDEBUG -arch x86_64 -arch i386 -isysroot
>>
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
>> -fPIC   -D _GNU_SOURCE -D _REENTRANT -I/sw/include -std=c++11
>> -fno-exceptions -Wno-sign-compare -Wno-unused-function
>> -Wno-unused-local-typedef -Wno-unused-value -Wno-unused-variable
>> -Wno-switch -Wno-covered-switch-default -Wno-deprecated-register
>> -Wno-gnu-anonymous-struct -Wno-unknown-pragmas
>> -Wno-missing-field-initializers -Wno-missing-braces -Wno-comment
>> -Wno-self-assign -Wno-vla-extension -Wno-format-pedantic -x c++ -o
>> CMakeFiles/omp.dir/kmp_alloc.c.o   -c
>>
/sw/src/fink.build/llvm40-4.0.0-1/llvm-4.0.0.src/projects/openmp/runtime/src/kmp_alloc.c
>>
>> The problem doesn't exist under cmake 3.6.2 because the openmp
build
>> doesn't append  -isysroot in that case.
>>               Jack
>> ps Note this seems to be related to using any SDK for -sysroot as
>> substituting...
>>
>> -isysroot
/Volumes/Xcode/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk
>>
>> from the Xcode 7.3.1 release also fails but substituting...
>>
>> -isysroot /
>>
>> or omitting -sysroot entirely allows the compilation to succeed. So it
>> seems that the openmp code doesn't like being compiled against SDKs
>> rather than / on darwin.