| This directory contains CI-specific tooling. | 
 |  | 
 | # Clang wrappers | 
 |  | 
 | CMake allows for compiler wrappers to be injected such as ccache, which | 
 | intercepts compiler calls and short-circuits on cache-hits.  This can be done | 
 | by specifying `CMAKE_C_COMPILER_LAUNCHER` and `CMAKE_CXX_COMPILER_LAUNCHER` | 
 | during CMake's configure step. Unfortunately, X-Code doesn't provide anything | 
 | like this, so we use basic wrapper scripts to invoke ccache + clang. | 
 |  | 
 | # Bazelrc files | 
 |  | 
 | In order to allow platform-specific `.bazelrc` flags during testing, we keep | 
 | 3 different versions here along with a shared `common.bazelrc` that they all | 
 | include.  Our GHA infrastructure will select the appropriate file for any test | 
 | and overwrite the default `.bazelrc` in our workspace, which is intended for | 
 | development only. |