For CI - switch off ccache for xcodebuild as it stalled the build.

Something has changed in the Travis Mac build environment and/or ccache that break our (hack) setup. So. temporarily switch ccache off until we can figure out what went wrong.

.travis.yml

@@ -511,7 +511,7 @@ branch: {name: OSX-CI, active: yes}
 language: objective-c
 cache:
   directories:
-    - $HOME/.ccache
+    # $HOME/.ccache
     - $HOME/initial-build-tree
 osx_image: xcode9.2
 env:
@@ -540,10 +540,12 @@ before_script:
   - if [[ $XCODE ]] && ([[ $RELEASE_TAG ]] || (! [[ $TRAVIS_BRANCH =~ [^-]+-[^-]+-CI ]] && echo $COMMIT_MESSAGE |grep -cq '\[ci package\]')); then export PACKAGE_UPLOAD=1; fi
   - brew update
   - which cmake >/dev/null 2>&1 || cmake=cmake
-  - travis_retry brew install ccache doxygen graphviz $cmake
+  # travis_retry brew install ccache doxygen graphviz $cmake
+  - travis_retry brew install doxygen graphviz $cmake
   - if [[ ! $cmake ]]; then brew outdated cmake || brew upgrade cmake; fi
-  - export PATH=$(brew info ccache |grep -o '\S*lib\S*'):$PATH
-  - if [[ $XCODE ]]; then pushd $(dirname $(xcodebuild -find-executable clang)) >/dev/null && sudo cp -p $(which ccache) . && for compiler in clang clang++; do sudo mv $compiler{,.orig} && sudo ln -sf $(pwd)/clang.orig /usr/local/bin/$compiler && sudo ln -sf ccache $compiler; done && popd >/dev/null && if [[ $IOS ]]; then redundant=AppleTV,Watch; elif [[ $TVOS ]]; then redundant=iPhone,Watch; else redundant=iPhone,AppleTV,Watch; fi && eval sudo rm -rf /Applications/Xcode.app/Contents/Developer/Platforms/{$redundant}{OS,Simulator}.platform; fi
+  # export PATH=$(brew info ccache |grep -o '\S*lib\S*'):$PATH
+  # if [[ $XCODE ]]; then pushd $(dirname $(xcodebuild -find-executable clang)) >/dev/null && sudo cp -p $(which ccache) . && for compiler in clang clang++; do sudo mv $compiler{,.orig} && sudo ln -sf $(pwd)/clang.orig /usr/local/bin/$compiler && sudo ln -sf ccache $compiler; done && popd >/dev/null && if [[ $IOS ]]; then redundant=AppleTV,Watch; elif [[ $TVOS ]]; then redundant=iPhone,Watch; else redundant=iPhone,AppleTV,Watch; fi && eval sudo rm -rf /Applications/Xcode.app/Contents/Developer/Platforms/{$redundant}{OS,Simulator}.platform; fi
+  - if [[ $XCODE ]]; then if [[ $IOS ]]; then redundant=AppleTV,Watch; elif [[ $TVOS ]]; then redundant=iPhone,Watch; else redundant=iPhone,AppleTV,Watch; fi && eval sudo rm -rf /Applications/Xcode.app/Contents/Developer/Platforms/{$redundant}{OS,Simulator}.platform; fi
   - rake ci_setup_cache
 script: rake ci && if [[ $PACKAGE_UPLOAD ]]; then rake ci_package_upload; fi && rake ci_timer
 after_script: rake ci_teardown_cache