diff --git a/bin/check-versions b/bin/check-versions
index ef81e29..0d12005 100755
--- a/bin/check-versions
+++ b/bin/check-versions
@@ -131,6 +131,17 @@ check_package() {
     return 1
   fi
 
+  # Different is not the same as newer. A checkout behind the published state
+  # — a stale branch, an un-pulled host — otherwise queues a REBUILD OF AN
+  # OLDER VERSION every cycle: the builder produces it, and promotion refuses
+  # it because that exact filename is already published with different bytes.
+  # If the artifact for this version already exists in the channel, there is
+  # nothing to build regardless of which direction the versions differ.
+  if compgen -G "$REPO_ROOT/$mirror/$ARCH/${pkg}-${pkgbuild_version}-*.pkg.tar."[!s]* >/dev/null 2>&1; then
+    print_warning "$pkg $pkgbuild_version is already published — this checkout is behind the channel; not queueing"
+    return 1
+  fi
+
   return 0
 }
 
diff --git a/helpers/basecamp-notifier.sh b/helpers/basecamp-notifier.sh
index 98470e2..aa8298f 100644
--- a/helpers/basecamp-notifier.sh
+++ b/helpers/basecamp-notifier.sh
@@ -17,17 +17,21 @@ release_chatbot_url() {
 
 notify_basecamp() {
   local content="$1"
-  local BASECAMP_CHATBOT_URL
-  BASECAMP_CHATBOT_URL=$(release_chatbot_url)
+  # NOT named BASECAMP_CHATBOT_URL: bash locals are visible to called
+  # functions, so declaring that name here would shadow the global that
+  # release_chatbot_url falls back to — and every notification would silently
+  # go nowhere for anyone who has only the legacy variable set.
+  local url
+  url=$(release_chatbot_url)
 
-  if [[ -z "${BASECAMP_CHATBOT_URL:-}" ]]; then
+  if [[ -z "$url" ]]; then
     return 0
   fi
 
   curl -s -o /dev/null \
     -H "Content-Type: application/json" \
     -d "$(jq -n --arg content "$content" '{content: $content}')" \
-    "$BASECAMP_CHATBOT_URL" 2>/dev/null || true
+    "$url" 2>/dev/null || true
 }
 
 basecamp_html_escape() {