message: docs(bazel): document an installation issue
  observed by Igor on a Mac
  PR Close
diff: @@ -73,3 +73,20 @@ The process should automatically connect to the debugger.
  - Run test: `bazel run packages/core/test:test_web`
  - Open chrome at: [http://localhost:9876/debug.html](http://localhost:9876/debug.html)
  - Open chrome inspector
  +
  +## FAQs
  +
  +Note: recent XCode update on Mac causes the following Bazel error
  +```
  +$ bazel build packages/...
  +ERROR: /private/var/tmp/_bazel_iminar/9b8801a4939e9750a817dc0cb35bbbca/external/local_config_cc/BUILD:50:5: in apple_cc_toolchain rule @local_config_cc//:cc-compiler-darwin_x86_64: Xcode version must be specified to use an Apple CROSSTOOL
  +ERROR: Analysis of target '//packages/core/test/render3:render3' failed; build aborted: Analysis of target '@local_config_cc//:cc-compiler-darwin_x86_64' failed; build aborted
  +```
  +To resolve the error do the following:
  +```
  +bazel clean --expunge
  +sudo xcode-select -s /Applications/Xcode.app/Contents/Developer
  +sudo xcodebuild -license
  +bazel build packages/...
  +```
  +Source: https://stackoverflow.com/questions/45276830/xcode-version-must-be-specified-to-use-an-apple-crosstool
  