Add nightly prereleases at midnight Eastern, skipping unchanged commits

packaging/nightly.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# Decide before building or assigning a nightly version. Checkout must include all tags.
+set -euo pipefail
+
+if [ "$GITHUB_EVENT_NAME" != schedule ]; then
+  echo 'build=true' >>"$GITHUB_OUTPUT"
+  exit 0
+fi
+
+# /releases/latest excludes prereleases. Include every published release instead,
+# including nightlies, and sort by publication time across all API pages.
+latest_tag="$(gh api --paginate --slurp "repos/$GITHUB_REPOSITORY/releases?per_page=100" \
+  --jq '[.[][] | select(.draft == false and .published_at != null)] | sort_by(.published_at) | last | .tag_name // empty')"
+if [ -n "$latest_tag" ]; then
+  # Resolve the tag itself, not target_commitish (which can be a moving branch).
+  released_sha="$(git rev-parse --verify "refs/tags/$latest_tag^{commit}")"
+  if [ "$released_sha" = "$GITHUB_SHA" ]; then
+    echo 'build=false' >>"$GITHUB_OUTPUT"
+    echo "### Nightly skipped: no new commits since $latest_tag" >>"$GITHUB_STEP_SUMMARY"
+    exit 0
+  fi
+fi
+
+echo 'build=true' >>"$GITHUB_OUTPUT"