[ci] fix R tests for macOS on Azure Pipelines

[StrikerRUS]

Fix current master fails.
Have no idea why it started to fail:

* installing *source* package ‘rlang’ ...
** package ‘rlang’ successfully unpacked and MD5 sums checked

** using staged installation
** libs
clang -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I./lib/  -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/usr/local/include  -fPIC  -Wall -g -O2  -c capture.c -o capture.o
clang -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I./lib/  -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/usr/local/include  -fPIC  -Wall -g -O2  -c export.c -o export.o
clang -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I./lib/  -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/usr/local/include  -fPIC  -Wall -g -O2  -c internal.c -o internal.o
clang -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I./lib/  -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/usr/local/include  -fPIC  -Wall -g -O2  -c lib.c -o lib.o
clang -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I./lib/  -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/usr/local/include  -fPIC  -Wall -g -O2  -c version.c -o version.o
clang -dynamiclib -Wl,-headerpad_max_install_names -undefined dynamic_lookup -single_module -multiply_defined suppress -L/Library/Frameworks/R.framework/Resources/lib -L/usr/local/lib -o rlang.so capture.o export.o internal.o lib.o version.o -F/Library/Frameworks/R.framework/.. -framework R -Wl,-framework -Wl,CoreFoundation
ld: malformed file
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/lib/libSystem.tbd:4:18: error: unknown enumerated scalar
platform:        zippered
                 ^~~~~~~~
 file '/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/lib/libSystem.tbd'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [rlang.so] Error 1
ERROR: compilation failed for package ‘rlang’

Refer to golang/go#31159 (comment).

[jameslamb]

😬 thanks @StrikerRUS ! Can you add a note in the title that this fixes the issue I opened? #2856

[StrikerRUS]

@jameslamb Oops! Didn't see we already have an issue for that. Just noticed failed master and googled the hotfix 😄

Fixed #2855.

[StrikerRUS]

Not sure that this fix is fully correct:

ld: warning: URGENT: building for OSX, but linking against dylib (/usr/lib/libc++.dylib) built for (unknown). Note: This will be an error in the future.
ld: warning: URGENT: building for OSX, but linking against dylib (/usr/lib/libSystem.dylib) built for (unknown). Note: This will be an error in the future.

(this is for the main library and it can potentially break our artifacts).
I think we should ping someone from Azure team to know what they had changed that we started to encounter this error.

[guolinke]

https://docs.microsoft.com/en-us/azure/devops/pipelines/agents/hosted?view=azure-devops

[guolinke]

BTW, it seems xcode9.4.1 is not supported in macos10.14. https://github.com/microsoft/azure-pipelines-image-generation/blob/master/images/macos/macos-10.14-Readme.md#installed-sdks

[StrikerRUS]

@guolinke

BTW, it seems xcode9.4.1 is not supported in macos10.14.

It is: https://github.com/microsoft/azure-pipelines-image-generation/blob/master/images/macos/macos-10.14-Readme.md#xcode

SDKs are something different: https://travis-ci.community/t/catalina-and-xcode-11-1-support/5392/2

[StrikerRUS]

Tried to install 10.13 SDK macOS_SDK_headers_for_macOS_10.13.pkg - no such package installer: Error - the package path specified was invalid: '/Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.13.pkg'. I guess we need either something like #2752, or fix at Azure side.

[StrikerRUS]

OK, due to we have some problems building R packages from sources on macOS (refer to #2752 and #2856 (comment)), I'm going to hotfix this by forcing installation of binary packages for macOS (even if they are a little bit outdated compared to CRAN sources).

@jameslamb Please feel free to propose a better long-term fix when you'll have time, but I'll merge this PR right after green CI checks (your outdated approval will allow me to do that 😃 ) as it blocks all other PRs.

[jameslamb]

OK, due to we have some problems building R packages from sources on macOS (refer to #2752 and #2856 (comment)), I'm going to hotfix this by forcing installation of binary packages for macOS (even if they are a little bit outdated compared to CRAN sources).

@jameslamb Please feel free to propose a better long-term fix when you'll have time, but I'll merge this PR right after green CI checks (your outdated approval will allow me to do that 😃 ) as it blocks all other PRs.

totally fine with me, thank you!