Add script to reproduce GitHub Actions runs locally

flake.nix

@@ -121,6 +121,7 @@
               coreutils
               curlMinimal.bin
               gitMinimal
+              gh                  # GitHub CLI tool
               gnutar
               foliage.packages.${system}.default
             ];

scripts/reproduce-github-actions-run.sh

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o pipefail
+
+usage() {
+	echo "Usage: $0 [GHA RUN ID] [(DERIVATION=allPackages)]"
+}
+
+REPO="input-output-hk/cardano-haskell-packages"
+
+ghaRunId="$1"
+derivation="${2:-allPackages}"
+
+if ! shift; then
+	usage
+	exit 0
+fi
+
+ARTIFACT_TEMP_DIR="$(mktemp -d)"
+trap '{ echo "Cleaning up $ARTIFACT_TEMP_DIR"; rm -rf -- "$ARTIFACT_TEMP_DIR"; }' EXIT
+
+echo "Downloading artifacts for run $ghaRunId in $ARTIFACT_TEMP_DIR"
+gh run download --repo "$REPO" "$ghaRunId" --dir "$ARTIFACT_TEMP_DIR"
+
+echo "Unpacking built-repo in $ARTIFACT_TEMP_DIR/_repo"
+mkdir "$ARTIFACT_TEMP_DIR/_repo"
+tar xf "$ARTIFACT_TEMP_DIR/built-repo/_repo.tar" -C "$ARTIFACT_TEMP_DIR/_repo"
+
+echo -n "Obtaining commit hash ..."
+headSha=$(gh run view --repo "$REPO" "$ghaRunId" --json headSha --jq .headSha)
+echo " $headSha"
+
+nix build \
+	"github:$REPO/${headSha}#${derivation}" \
+	--override-input CHaP "path:$ARTIFACT_TEMP_DIR/_repo" \
+	--accept-flake-config true \
+	--print-build-logs --show-trace