diff --git a/src/build/index.js b/src/build/index.js
index 1ce756b4..e2cffc9b 100644
--- a/src/build/index.js
+++ b/src/build/index.js
@@ -102,8 +102,13 @@ exports.build = function (appPath, argv, cb) {
         return logger.error('another build is already in progress');
       }
 
-      logger.error(err);
-      logger.log('build failed');
+      logger.info('build failed');
+      logger.error('exception: ' + err.stack);
+      if (process.send) {
+        process.send({
+          err: err.stack
+        });
+      }
       process.exit(1);
     })
     .success(function () {
diff --git a/src/serve/appRoutes.js b/src/serve/appRoutes.js
index 8252cebb..962c0512 100644
--- a/src/serve/appRoutes.js
+++ b/src/serve/appRoutes.js
@@ -115,6 +115,12 @@ exports.addToAPI = function (opts, api) {
                 );
               });
             }
+          })
+          .catch(function(e) {
+            logger.error('Error building app', e);
+            res.status(500).send({
+              message: e
+            });
           });
       })
       .catch(function (e) {
diff --git a/src/serve/buildQueue.js b/src/serve/buildQueue.js
index acff9687..0f78c5ed 100644
--- a/src/serve/buildQueue.js
+++ b/src/serve/buildQueue.js
@@ -74,7 +74,7 @@ var BuildItem = Class(function () {
 
     logger.log('starting build', this.appPath, this.buildOpts.target);
 
-    this._build = childProcess.fork(buildFork, [(args)])
+    this._build = childProcess.fork(buildFork, [args])
       .on('message', this._onFinish.bind(this))
       .on('close', this._onClose.bind(this));
   };
@@ -118,7 +118,9 @@ var BuildItem = Class(function () {
     // if the fork terminated normally, done will be true here
     if (this.done) { return; }
 
-    this._reject({message: 'build failed'});
+    this._reject({
+      message: 'build failed (closed before done)'
+    });
     this.done = true;
     if (this._onStop) {
       this._onStop();
diff --git a/src/web/Simulator.js b/src/web/Simulator.js
index 5e27a5d9..d639a423 100644
--- a/src/web/Simulator.js
+++ b/src/web/Simulator.js
@@ -234,6 +234,14 @@ var Simulator = exports = Class(function () {
       }, function (err) {
         this.logger.error('Unable to simulate', this._app);
         this.logger.error(err);
+
+        this._requiresHardRebuild = true;
+
+        if (err.response && err.response.message) {
+          this._ui.showBuildFailed(err.response.message);
+        } else {
+          this._ui.showBuildFailed('Unknown failure, please check devkit server logs.');
+        }
       });
   });
 
diff --git a/src/web/stylesheets/simulator.styl b/src/web/stylesheets/simulator.styl
index 882c8a9b..e81e230d 100644
--- a/src/web/stylesheets/simulator.styl
+++ b/src/web/stylesheets/simulator.styl
@@ -295,6 +295,16 @@ else
     width 100%
     height 100%
 
+  #buildFailedContainer
+    position absolute
+    top 0px
+    left 0px
+    width 100%
+    height 100%
+    padding 20px
+    background rgba(40, 0, 0, 0.7)
+    word-wrap break-word
+
   .spinnerContainer
     position absolute
     top 0px
diff --git a/src/web/ui/Chrome.js b/src/web/ui/Chrome.js
index 12e3af00..cd7a018a 100644
--- a/src/web/ui/Chrome.js
+++ b/src/web/ui/Chrome.js
@@ -60,6 +60,10 @@ exports = Class(CenterLayout, function (supr) {
         {id: 'background', type: FrameBackground},
         {id: 'splashImage'},
         {id: 'resizeHandle'},
+        {id: 'buildFailedContainer', children: [
+          {tag: 'h3', text: 'Build failed'},
+          {id: 'buildFailedMessage', tag: 'p', text: '<message>'}
+        ]},
         {id: 'build-spinner', class: 'spinnerContainer', children: [
           {class: 'spinner'},
           {tag: 'p', text: 'Building app'}
@@ -90,6 +94,8 @@ exports = Class(CenterLayout, function (supr) {
   this.buildWidget = function () {
     supr(this, 'buildWidget', arguments);
 
+    $.style(this['buildFailedContainer'], {display: 'none'});
+
     var opts = this._opts;
 
     this._validOrientations = {};
@@ -223,10 +229,11 @@ exports = Class(CenterLayout, function (supr) {
   };
 
   this.setBuilding = function (isBuilding) {
-
     // Make sure we remove game simulation overhead when building
     this.setPaused(isBuilding);
 
+    $.style(this['buildFailedContainer'], {display: 'none'});
+
     var spinner = this['build-spinner'];
 
     if (!isBuilding) {
@@ -245,6 +252,13 @@ exports = Class(CenterLayout, function (supr) {
     }
   };
 
+  this.showBuildFailed = function(msg) {
+    $.style(this['buildFailedContainer'], {display: 'block'});
+    $.removeClass(this['build-spinner'], 'visible');
+
+    $.setText(this.buildFailedMessage, msg);
+  };
+
   this._onMenuOpen = function (menu) {
     $.addClass(this.toolbar, 'menu-open');
     if (menu == this.overflowMenu) {