add output diffs

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

utils/diff-evals.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env nix
+#! nix shell nixpkgs#bash nixpkgs#gnugrep nixpkgs#nvd --command bash
+
+# diffs each derivation
+
+set -x
+set -v
+set -e
+
+script_path=$(dirname "$(readlink -f $0)")
+parent_path=$(dirname "$script_path")
+
+readarray -t pre_drv < "$parent_path/pre-drv"
+readarray -t post_drv < "$parent_path/post-drv"
+
+post_drv_path="$parent_path/post-diff"
+# cleanup any files with the same name
+rm "$post_drv_path" || true
+touch "$post_drv_path"
+
+for i in $(seq 0 $(( "${#pre_drv[@]}" -1 ))); do
+    echo "Diffing updates to $(echo "${pre_drv[$i]}" | cut -f 2- -d '-')" >> "$post_drv_path"
+    nvd diff "${pre_drv[$i]}" "${post_drv[$i]}" >> "$post_drv_path"
+done

utils/eval-to-drv.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env nix
+#! nix shell nixpkgs#bash nixpkgs#gnugrep --command bash
+
+# diffs each derivation
+
+set -x
+set -v
+set -e
+
+if [ "$#" -ne 2 ]; then
+    echo "$0 (pre|post)"
+fi
+
+script_path=$(dirname "$(readlink -f $0)")
+parent_path=$(dirname "$script_path")
+out_path="$parent_path/$1-drv"
+
+
+drv=$(nix flake check --verbose 2> >(grep -P -o "derivation evaluated to (/nix/store/.*\.drv)" | grep -P -o "/nix/store/.*\.drv"))
+
+echo "$drv" > "$out_path"