Skip stale latest prebuilts in installers

install.sh

@@ -222,6 +222,73 @@ release_latest_tag_download_url() {
   esac
 }
 
+version_part() {
+  version="$1"
+  index="$2"
+  printf '%s\n' "$version" \
+    | sed 's/[^0-9][^0-9]*/ /g' \
+    | awk -v index="$index" '{ value=$index; if (value == "") value=0; print value }'
+}
+
+version_less_than() {
+  left="$1"
+  right="$2"
+  for index in 1 2 3 4 5 6 7 8; do
+    lpart="$(version_part "$left" "$index")"
+    rpart="$(version_part "$right" "$index")"
+    if [ "$lpart" -lt "$rpart" ]; then
+      return 0
+    fi
+    if [ "$lpart" -gt "$rpart" ]; then
+      return 1
+    fi
+  done
+  return 1
+}
+
+current_source_version() {
+  if [ -f Cargo.toml ]; then
+    sed -n 's/^version = "\(.*\)"/\1/p' Cargo.toml | sed -n '1p'
+    return 0
+  fi
+  [ -n "$repo" ] || return 1
+  web_base="$(repo_web_base "$repo")" || return 1
+  curl -fsSL "$web_base/raw/branch/main/Cargo.toml" 2>/dev/null \
+    | sed -n 's/^version = "\(.*\)"/\1/p' \
+    | sed -n '1p'
+}
+
+latest_release_tag() {
+  [ -n "$repo" ] || return 1
+  web_base="$(repo_web_base "$repo")" || return 1
+  latest_url="$(curl -fsSL -o /dev/null -w '%{url_effective}' "$web_base/releases/latest" 2>/dev/null || true)"
+  case "$latest_url" in
+    "$web_base"/releases/tag/*)
+      tag="${latest_url##"$web_base"/releases/tag/}"
+      [ -n "$tag" ] || return 1
+      printf '%s\n' "$tag"
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}
+
+latest_release_is_stale() {
+  if [ -n "$binary_url" ] || [ -n "$binary_base" ] || [ "$binary_version" != "latest" ]; then
+    return 1
+  fi
+  latest="$(latest_release_tag || true)"
+  current="$(current_source_version || true)"
+  [ -n "$latest" ] && [ -n "$current" ] || return 1
+  latest="${latest#v}"
+  if version_less_than "$latest" "$current"; then
+    echo "latest release $latest is older than source $current; skipping stale prebuilt" >&2
+    return 0
+  fi
+  return 1
+}
+
 find_extracted_binary() {
   find "$1" -type f -name "$2" 2>/dev/null | sed -n '1p'
 }
@@ -312,6 +379,9 @@ verify_archive_version() {
 }
 
 try_install_prebuilt() {
+  if latest_release_is_stale; then
+    return 1
+  fi
   download_url="$(release_latest_tag_download_url || release_download_url)" || return 1
   tmpdir="$(mktemp -d)"
   archive="$tmpdir/$(release_artifact_name)"