Skip stale latest prebuilts in installers

tests/release_scripts.rs

@@ -19,6 +19,27 @@ fn release_scripts_skip_stale_artifacts_when_auto_discovering() {
     assert!(publish.contains("actual=\"$(artifact_version \"$artifact\" || true)\""));
 }
 
+#[test]
+fn installers_skip_stale_latest_release_prebuilts() {
+    let install = include_str!("../install.sh");
+    assert!(install.contains("latest_release_is_stale"));
+    assert!(install.contains("current_source_version"));
+    assert!(install.contains("latest release $latest is older than source $current"));
+    assert!(
+        install.contains("if latest_release_is_stale; then"),
+        "unix installer must skip stale latest before downloading a prebuilt"
+    );
+
+    let ps1 = include_str!("../install.ps1");
+    assert!(ps1.contains("Latest-ReleaseIsStale"));
+    assert!(ps1.contains("Current-SourceVersion"));
+    assert!(ps1.contains("latest release $latestVersion is older than source $current"));
+    assert!(
+        ps1.contains("if (Latest-ReleaseIsStale)"),
+        "windows installer must skip stale latest before downloading a prebuilt"
+    );
+}
+
 #[test]
 fn package_check_verifies_only_artifacts_it_builds() {
     let makefile = include_str!("../Makefile");