error stack loader option, plugin loader normalization fix, alias and loader to use usual resolution

lib/amd-helpers.js

@@ -79,7 +79,7 @@ hookConstructor(function(constructor) {
           normalized = normalized.substr(0, normalized.length - 3);
         var module = loader.get(normalized);
         if (!module)
-          throw new Error('Module not already loaded loading "' + names + '" from "' + referer + '".');
+          throw new Error('Module not already loaded loading "' + names + '" as ' + normalized + (referer ? ' from "' + referer + '".' : '.'));
         return module.__useDefault ? module['default'] : module;
       }
 

lib/core.js

@@ -64,6 +64,7 @@ hookConstructor(function(constructor) {
     this.warnings = false;
     this.defaultJSExtensions = false;
     this.pluginFirst = false;
+    this.loaderErrorStack = false;
 
     // by default load ".json" files as json
     // leading * meta doesn't need normalization
@@ -291,9 +292,18 @@ hook('instantiate', function(instantiate) {
 */
 SystemJSLoader.prototype.env = 'development';
 
+var curCurScript;
 SystemJSLoader.prototype.config = function(cfg) {
   var loader = this;
 
+  if ('loaderErrorStack' in cfg) {
+    curCurScript = $__curScript;
+    if (cfg.loaderErrorStack)
+      $__curScript = undefined;
+    else
+      $__curScript = curCurScript;
+  }
+
   if ('warnings' in cfg)
     loader.warnings = cfg.warnings;
 
@@ -432,7 +442,7 @@ SystemJSLoader.prototype.config = function(cfg) {
   for (var c in cfg) {
     var v = cfg[c];
 
-    if (c == 'baseURL' || c == 'map' || c == 'packages' || c == 'bundles' || c == 'paths' || c == 'warnings' || c == 'packageConfigPaths')
+    if (c == 'baseURL' || c == 'map' || c == 'packages' || c == 'bundles' || c == 'paths' || c == 'warnings' || c == 'packageConfigPaths' || c == 'loaderErrorStack')
       continue;
 
     if (typeof v != 'object' || v instanceof Array) {

lib/package.js

@@ -58,13 +58,6 @@
  * - map targets support conditional interpolation ('./x': './x.#{|env}.js')
  * - internal package map targets cannot use boolean conditionals
  *
- * In addition, the following modules properties will be allowed to be package
- * -relative as well in the package module config:
- *
- *   - loader
- *   - alias
- *
- *
  * Package Configuration Loading
  *
  * Not all packages may already have their configuration present in the System config
@@ -616,11 +609,6 @@
               extendMeta(meta, matchMeta, matchDepth && bestDepth > matchDepth);
             });
 
-            // allow alias and loader to be package-relative
-            if (meta.alias && meta.alias.substr(0, 2) == './')
-              meta.alias = pkgName + meta.alias.substr(1);
-            if (meta.loader && meta.loader.substr(0, 2) == './')
-              meta.loader = pkgName + meta.loader.substr(1);
             extendMeta(load.metadata, meta);
           }
         }

lib/plugins.js

@@ -132,6 +132,18 @@
       }
 
       return locate.call(loader, load)
+      .then(function(address) {
+        if (pluginSyntaxIndex != -1 || !load.metadata.loader)
+          return address;
+
+        // normalize plugin relative to parent in locate here when
+        // using plugin via loader metadata
+        return loader.normalize(load.metadata.loader, load.name)
+        .then(function(loaderNormalized) {
+          load.metadata.loader = loaderNormalized;
+          return address;
+        });
+      })
       .then(function(address) {
         var plugin = load.metadata.loader;