message: Do not clobber VK_ICD_FILENAMES.
  Fixes
diff: @@ -38,8 +38,13 @@ bool loadLibrary() {
  // executable lives in. This allows MacOS users to run Vulkan-based Filament apps from anywhere.
  const Path executableFolder = Path::getCurrentExecutable().getParent();
  const Path dylibPath = executableFolder.concat(VKLIBRARY_PATH);
  +
  + // Provide a value for VK_ICD_FILENAMES only if it has not already been set.
  + const char* icd = getenv("VK_ICD_FILENAMES");
  + if (icd == nullptr) {
  const Path jsonPath = executableFolder.concat("MoltenVK_icd.json");
  setenv("VK_ICD_FILENAMES", jsonPath.c_str(), 1);
  + }
  #else
  const Path dylibPath = FILAMENT_VKLIBRARY_PATH;
  #endif
  