| os_version == 10.13.5 # Oldest CI nodes are currently 10.13.3 | |
| brew cmake >= 3.11.2 # LLVM docs state this is the minimum version required. | |
| brew ninja >= 1.8.2 # Stage2 verbose output | |
| pip psutil >= 5.4.5 # Required for timeouts in the GTest Suite. | |
| pip six >= 1.11.0 # Required for urllib | |
| xcode == 9.4.1 |