I was following your instructions to build sample firebase cocos2d-x project for Analytics and got this error:

sample/sample_project/cocos2d/cocos/platform/CCFileUtils.cpp:1156:9: error: call to unavailable function 'system': not available on iOS
    if (system(command.c_str()) >= 0)
        ^~~~~~

You guys need to cherry pick this fix to resolve the issue: remove "system" usage #17921 which I applied locally and was able to get the project build and run.