This function is not, and never have been, used anywhere inside nixpkgs, outside of bootstrapping setupcfg2nix itself.
It was added in https://github.com/NixOS/nixpkgs/pull/38778 by @shlevy.
It has no out-of-tree users on Github either. External breakage is not expected.
As we continue iterating on Python infrastructure for Python 3, some
code is starting to diverge for Python 2. If we copy the current state
of mk-python-derivation.nix and freeze it for Python 2, we can iterate
on it for Python 3 with more freedom.
fetchPypi doesn't use python under the hood and doesn't need to be tied
to a specific version of python. Moving it to top level makes it more
consistent with other fetchers and makes code generation easier.
This adds a test to ensure no new uses of `buildPythonApplication` can
be added to `python-packages.nix`.
Python packages can be grouped into two groups: 1) applications and 2)
packages providing importable modules. In `python-packages.nix` we only
want to have 2). 1) should be in the top-level package set.
To achieve this, all setup hooks need to be marked as being a setup hook.
For the setup hooks in the Python packages set this is done by creating
a new builder, `makePythonHook`.
Because there were issues with splicing, the file importing all the hooks
is converted to an extension. All non-packages were moved out of `python-packages.nix`
into `python-packages-base.nix`. The `keep` argument to `makeScopeWithSplicing
was cleaned up as well; there is no need to keep this one manually in sync
reducing the risk of breaking cross-compilation.
