replace update-carnix.sh

Crate2nix hasn't been added to nixpkgs yet so it needs to be pulled in
separately.

README.md

@@ -214,8 +214,8 @@ Currently there is no easy way to set up a test instance of ofborg. If `cargo
 check` and `cargo test` both succeed, feel free to Pull Request your changes.
 Make sure to format your code with `cargo fmt` and check for additional warnings
 with `cargo clippy`. If you added, removed, or updated the dependencies, also be
-sure to update Carnix by running
-[`./nix/update-carnix.sh`](./nix/update-carnix.sh).
+sure to update Cargo.nix by running
+[`./nix/update-crates.sh`](./nix/update-crates.sh).
 
 To disable warnings as errors, run your command with an empty `RUSTFLAGS`. For
 example:

default.nix

@@ -57,14 +57,13 @@ in
 
 
     Build failed because you bumped the Cargo
-    version without regenerating the carnix
-    file.
+    version without regenerating the Cargo.nix.
 
     Run:
 
 
 
-        nix-shell --run ./nix/update-carnix.sh
+        nix-shell --run ./nix/update-crates.sh
 
 
     and commit those changes.

nix/update-carnix.sh

@@ -1,6 +0,0 @@
-#!/bin/sh
-
-set -eu
-
-cargo build
-carnix generate-nix --src .

nix/update-crates.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -E "with import <nixpkgs> {}; mkShell { nativeBuildInputs = [ (import (builtins.fetchTarball https://github.com/kolloch/crate2nix/archive/0.8.0.tar.gz) {}) ]; }"
+set -e
+
+cargo build
+crate2nix generate