I have personally not built Python myself (though I've built many an extension), but what I can say is that I got the idea from Larry Hastings. According to him (this if for the Gilectomy fork):

"Second, as you hack on the Gilectomy you may break your "python" executable rather badly. This is of course expected. However, the python Makefile itself depends on having a working local python interpreter, so when you break that you often break your build too."

2017-09-30 19:59 GMT-05:00 Donald Stufft <donald@stufft.io>:

On Sep 30, 2017, at 3:52 PM, xoviat <xoviat@gmail.com> wrote:

I don't think CPython needs to bundle all of its build-time dependencies. That principle doesn't really apply to other Python programs nor most other programs in general. AFAIK, CPython already has a build-time dependency on another, external, Python, so it wouldn't be too much to require the external Python to have setuptools installed with something like pyproject.toml (other programming languages usually bootstrap themselves with previous versions of the language along with some associated build tools).

As far as I can tell, CPython does *not* have a build time dependency on having Python available. I just spun up a bare alpine linux container and compiled CPython `master` branch on it. As far as I can tell the only Python that exists in this container is the one I just compiled.

That means that in order for CPython to depend on distutils to build as you indicate, it would also need to start depending on an existing version of Python being available. I don’t think that’s a great idea. I think Python should not depend on Python to build.