This has been moved to the Matrix AI blog: https://matrix.ai/2018/03/24/developing-with-nix/
Note that if you just to compile a simple C program, and you don't want to fiddle with environments:
nix-shell --packages stdenvThat's enough to enter an environment with stdenv.
I've read only the Python section. You may want to add
to shellhook, because otherwise pip can fail with Zip error (NixOS/nixpkgs@6f1551d)