diff --git a/tools/isobuild/bundler.js b/tools/isobuild/bundler.js
index 415b4c65e2..2f63938616 100644
--- a/tools/isobuild/bundler.js
+++ b/tools/isobuild/bundler.js
@@ -3295,17 +3295,13 @@ async function bundle({
         buildMode: buildOptions.buildMode
       });
 
-      try {
-        await client.make({
-          packages: [app],
-          minifyMode: minifyMode,
-          minifiers: options.minifiers || [],
-          addCacheBusters: true,
-          onJsOutputFiles,
-        });
-      } catch (e) {
-        // it's fine to fail here, but we don't want to propagate the error
-      }
+      await client.make({
+        packages: [app],
+        minifyMode: minifyMode,
+        minifiers: options.minifiers || [],
+        addCacheBusters: true,
+        onJsOutputFiles,
+      });
 
       return client;
     });
diff --git a/tools/runners/run-app.js b/tools/runners/run-app.js
index d00ab78308..6bbed38ec9 100644
--- a/tools/runners/run-app.js
+++ b/tools/runners/run-app.js
@@ -405,7 +405,15 @@ Object.assign(AppRunner.prototype, {
 
     self.isRunning = true;
     global.asyncLocalStorage.run({}, () =>
-        self._runApp().catch((e) => self._resolvePromise("start", e))
+        self._runApp()
+          .catch((e) => {
+            // There was an unexpected error when building the app
+            // This is not recoverable, so we turn it into an unhandled exception
+            // and crash.
+            setTimeout(() => {
+              throw e;
+            });
+          })
     );
     await self.startPromise;
     self.startPromise = null;
@@ -435,9 +443,6 @@ Object.assign(AppRunner.prototype, {
       ee.emit(name, value);
       this._promiseResolvers[name] = null;
     }
-    if (value instanceof Error) {
-      throw value;
-    }
   },
 
   _cleanUpPromises: function () {