collision ?

[asmodehn]

Using this overlay (via (python36.withPackages (ps: with ps; [ azure-cli ])) in buildInputs of a mkShell derivation), I get a collision between two azure-cli related packages :

building '/nix/store/yq8yalq8ad864jh9ljq0y61914n1qfx1-python3-3.6.6-env.drv'...
collision between `/nix/store/gw491p587z32mlrm122xc8vsq5snldq3-python3.6-azure-cli-extension-0.2.1/lib/python3.6/site-packages/azure/cli/__pycache__/__init__.cpython-36.pyc' and `/nix/store/f740dpb3g8qi8g166cc80xqkkkr99gyg-python3.6-azure-cli-core-2.0.43/lib/python3.6/site-packages/azure/cli/__pycache__/__init__.cpython-36.pyc'
builder for '/nix/store/yq8yalq8ad864jh9ljq0y61914n1qfx1-python3-3.6.6-env.drv' failed with exit code 25
error: build of '/nix/store/yq8yalq8ad864jh9ljq0y61914n1qfx1-python3-3.6.6-env.drv' failed

Using it with (with python36Packages; [ azure-cli ]) installs fine however, but breaks on usage :

[nix-shell:~]$ az
/nix/store/bwfygfcdvis9wd1c1v51xwnwhw1hx0a0-python3-3.6.6/bin/python: No module named azure.cli

Any hint ?

[asmodehn]

Since this is a namespace package, the proper way to do things (given how nix messes around with PYTHONPATH) is to have all the package in the same site-packages location.
I would advise a deeper look at importlib to figure out how python's import works.

And apparently this does work (thanks @duog ):

{pkgs ? import <nixpkgs> {
 overlays = [ (import ./nix/azure-cli-nix) ];
}}: let
 python = pkgs.python36.buildEnv.override {
   extraLibs = with pkgs.python36Packages; [ azure-cli];
   ignoreCollisions = true;
} ;

in pkgs.mkShell {
 name = "env";
 buildInputs = [ python ];
}

Next step would be figuring out where the collisions come from exactly...

[asmodehn]

I accidentally noticed that current nixpkgs solves this problem slightly differently : https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/python-modules/azure-mgmt-compute/default.nix#L24