fawltydeps: add update script

pkgs/fawltydeps/default.nix

@@ -36,12 +36,12 @@ let
   src = fetchFromGitHub {
     owner = "tweag";
     repo = "FawltyDeps";
-    rev = "0201e74a158c5774db9150e1e70f01e76bad34e7";
+    rev = "f8b156756b1de47c578935c4d6f6a7a8f2975c63";
-    sha256 = "sha256-kSAy6IOS+G+e7hG4ZseglhOsnJ7Tg87MaMRCWUoSJdA=";
+    sha256 = "sha256-3oQX0oX1+jZAC+vTRd7dUGNfioc6ADFmF+GSbvVyYsQ=";
   };
 in
 poetry2nix.mkPoetryApplication {
-  version = "2023-03-14";
+  version = "2023-03-16";
   python = python39;
   projectDir = "${src}";
   overrides = poetryOverrides;

pkgs/fawltydeps/update.sh

@@ -0,0 +1,32 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i bash -p nix-prefetch-github gnused jq
+
+function help() {
+  echo "Regenerates packaging data for the fawltydeps package."
+  echo "Usage: $0 <rev>"
+  exit 1
+}
+
+if [[ $# -gt 1 || $1 == -* ]]; then
+  help
+fi
+
+set -x
+
+cd "$(dirname "$0")"
+version="$1"
+
+set -euo pipefail
+
+if [ -z "$version" ]; then
+  help
+fi
+
+src_hash=$(nix-prefetch-github tweag FawltyDeps --rev  "${version}" | jq -r .sha256)
+src_hash=$(nix hash to-sri --type sha256 "$src_hash")
+
+sed -i -E -e "s#rev = \".*\"#rev = \"$version\"#" default.nix
+sed -i -E -e "s#sha256 = \".*\"#sha256 = \"$src_hash\"#" default.nix
+sed -i -E -e "s#version = \".*\"#version = \"$(date +%Y-%m-%d)\"#" default.nix
+
+