pythonPackages: ensure all derivations provide python modules

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.

1 files changed, 1 insertions, 1 deletions

diff --git a/pkgs/top-level/python2-packages.nix b/pkgs/top-level/python2-packages.nix
index f0faf2b1cd1f5..773f8d860f0a6 100644
--- a/pkgs/top-level/python2-packages.nix
+++ b/pkgs/top-level/python2-packages.nix
@@ -7,7 +7,7 @@ self: super:
 with self; with super; {
   attrs = callPackage ../development/python2-modules/attrs { };
 
-  bootstrapped-pip = callPackage ../development/python2-modules/bootstrapped-pip { };
+  bootstrapped-pip = toPythonModule (callPackage ../development/python2-modules/bootstrapped-pip { });
 
   boto3 = callPackage ../development/python2-modules/boto3 {};