but when I try to build the environment first, and then drop into bash that doesn't work. So when I do

RUN nix-build /home/renv/default.nix
CMD ["bash"]

I get following error message

112.8 unpacking sources
112.8 unpacking source archive /nix/store/2zdq28c97x3rqb7fqrrvwkdzh44pdq05-nix-2.13.3
113.0 source root is nix-2.13.3
113.0 patching sources
113.0 configuring
113.1 no configure script, doing nothing
113.1 building
113.1 no Makefile or custom buildPhase, doing nothing
113.1 installing
113.1 no Makefile or custom installPhase, doing nothing
113.1 post-installation fixup
113.4 error: builder for '/nix/store/1csmqrnlgbyzm5kkjw2s9q348qpx3rqy-myProject.drv' failed to produce output path for output 'out' at '/nix/store/icf4fsmlcalyc2v5wiwn88x6f7xab46y-myProject'

ok so some more googling led me to write this default.nix:

ok so some more googling led me to write this default.nix:

{ pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/e11142026e2cef35ea52c9205703823df225c947.tar.gz") {} }:

with pkgs;

let
  my-pkgs = rWrapper.override {
    packages = with rPackages; [ dplyr ggplot2 R];
  };
in
mkShell {
  buildInputs = [my-pkgs];
}

In reply to @brodriguesco:matrix.org
I guess the issue was that before I wasn't creating an environment, because I wasn't using mkShell explicitely?

In reply to @petrichor:envs.net
is there a standard way to install an old version of a python package? equivalent to pip install jupyter-server<2.0.0

In reply to @raitobezarius:matrix.org
or not using nixpkgs

Any easy way of setting up an ad-hoc Python environment with a few packages on the command line with nix run

I'm able to get nix run nixpkgs#jupyter working but can't get NumPy into a kernel without writing a shell.nix or similar first. Was thinking nix run 'nixpkgs#python3.withPackages(ps: with ps; [torch])' could work but it doesn't seem to.

Guess this is one area where nix-shell is still better?

nix-shell -p 'python310.withPackages (p: [ p.numpy ])' does what I expect.