provide post-build hook capability prior to creating .tar.gz

There are several cases I can imagine for this. In my case, I have a very common one.

We have the well-known issue where the bundled urllib leverages the bundled openssl which comes with no certificate file, and thus cannot verify any certificates out of the box.

With a post-build hook, we could export a cacert.pem file from the system or from another location and bundle it with the .tar.gz. That would also require us patching some source somewhere to instruct the bundled openssl to use it. There are a few options for that part.

Obviously, we can un-tar, modify, and re-tar, but I don't want to do that.

Another common case I can imagine would be to do pip install of some extra packages prior to bundling (I'm not sure if that can actually work or not, but I believe so.).

Alternatively, if you'd prefer to provide some first-class mechanism for solving the "lack of a bundled cacert" problem, that would help us with the immediate issue so that would be great as well.

Anyway, feedback welcome.

该 issue 未指定任何文件、测试或构建入口点。首先定位创建 .tar.gz 的构建步骤，并审查捆绑文件和软件包的组装方式。完成标准是：有一个有文档记录的构建后阶段可以在归档前修改捆绑包，并且有经过测试的添加 cacert.pem 等文件的路径。