[Question] How to create prebuilt version of sdk from scripts

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### [REQUIRED] Please fill in the following fields:

* Pre-built SDK from the [website](https://firebase.google.com/download/cpp) or open-source from this repo: open-source from this repo
* Firebase C++ SDK version: 12.5.0
* Main Firebase Components in concern: all
* Other Firebase Components in use: all
* Platform you are using the C++ SDK on: Linux
* Platform you are targeting: desktop (iOS, Android, and/or desktop)

### [REQUIRED] Please describe the question here:

What's up guys. Sorry for stupid (maybe) question.

I build firebase sdk from sources.
How can I get prebuilt versrion of sdk from script?

I invoke:
`./build_scripts/desktop/package.sh -b /home/era/Work/firebase-cpp-sdk/build -o /home/era/Work/firebase-cpp-sdk/release -p linux -t /usr/bin -j 28 -L`

But, there are no some include files and folders. Here what i get.



But, if we look at the prebuilt version of sdk (zip file) you will see more files
For ex, the include files from prebuilt version


As you can see, there are more files.
What I do wrong?

build_scripts/desktop/package.sh から始め、指定された build パスと出力パスを使って提示されたコマンドを再現します。生成された include ツリーをダウンロードした prebuilt SDK と比較し、どの packaging 入力が差異を制御しているかを追跡します。正しい invocation を特定するか、repository 側の packaging の不足を文書化できれば完了です。

索引モデルが issue の本文から書いたものです。