From 3390a00b49c513a6da60f48044462118436130f8 Mon Sep 17 00:00:00 2001
From: Vojta Jina <vojta.jina@gmail.com>
Date: Thu, 27 Jun 2013 18:52:47 -0700
Subject: [PATCH] fix(preprocessor): better errors when loading preprocessors

---
 lib/preprocessor.js | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/preprocessor.js b/lib/preprocessor.js
index e64826d7b..40430ddfa 100644
--- a/lib/preprocessor.js
+++ b/lib/preprocessor.js
@@ -26,12 +26,17 @@ var createPreprocessor = function(config, basePath, injector) {
 
       preprocessors.shift()(content, file, nextPreprocessor);
     };
-    var instantiatePreprocessor = function(preprocessorName) {
+    var instantiatePreprocessor = function(name) {
       try {
-        preprocessors.push(injector.get('preprocessor:' + preprocessorName));
+        preprocessors.push(injector.get('preprocessor:' + name));
       } catch (e) {
         // TODO(vojta): log warning only once per each preprocessor
-        log.warn('Pre-processor "%s" is not registered!', preprocessorName);
+        if (e.message.indexOf('No provider for "preprocessor:' + name + '"') !== -1) {
+          log.warn('Can not load "%s", it is not registered!\n  ' +
+                   'Perhaps you are missing some plugin?', name);
+        } else {
+          log.warn('Can not load "%s"!\n  ' + e.stack, name);
+        }
       }
     };