diff --git a/tools/bundler.js b/tools/bundler.js
index 5aaa0bf249..6716309e13 100644
--- a/tools/bundler.js
+++ b/tools/bundler.js
@@ -700,13 +700,13 @@ _.extend(Bundle.prototype, {
  *
  * - releaseStamp : The Meteor release version to use. This is *ONLY*
  *                  used as a stamp (eg Meteor.release). The package
- *                  search path is configured with packageSearchOptions.
+ *                  search path is configured with 'library'.
  *
  * - library : Package library to use to fetch any required
  *   packages. NOTE: if there's an appDir here, it's used for package
  *   searching but it is NOT the appDir that we bundle!  So for
  *   "meteor test-packages" in an app, appDir is the test-runner-app
- *   but packageSearchOptions.appDir is the app the user is in.
+ *   but library.appDir is the app the user is in.
  */
 exports.bundle = function (app_dir, output_path, options) {
   if (!options)
diff --git a/tools/meteor.js b/tools/meteor.js
index fd8117a8a2..5d729f0969 100644
--- a/tools/meteor.js
+++ b/tools/meteor.js
@@ -86,10 +86,10 @@ Fiber(function () {
           "Please check to make sure that you are online.");
       }
     }
-    context.packageSearchOptions = {
+    context.library = new packages.Library({
       appDir: context.appDir,
       releaseManifest: context.releaseManifest
-    };
+    });
   };
 
   var calculateReleaseVersion = function (argv) {
@@ -479,7 +479,7 @@ Fiber(function () {
       }
 
       requireDirInApp('add');
-      var all = (new packages.Library(context.packageSearchOptions)).list();
+      var all = context.library.list();
       var using = {};
       _.each(project.get_packages(context.appDir), function (name) {
         using[name] = true;
@@ -565,7 +565,7 @@ Fiber(function () {
       }
 
       requireDirInApp('list');
-      var list = (new packages.Library(context.packageSearchOptions)).list()
+      var list = context.library.list();
       var names = _.keys(list);
       names.sort();
       var pkgs = [];
@@ -610,7 +610,7 @@ Fiber(function () {
         nodeModulesMode: 'copy',
         minify: true,  // XXX allow --debug
         releaseStamp: context.releaseVersion,
-        library: new packages.Library(context.packageSearchOptions)
+        library: context.library
       });
       if (errors) {
         process.stdout.write("Errors prevented bundling:\n");
@@ -763,7 +763,7 @@ Fiber(function () {
             nodeModulesMode: 'skip',
             minify: !new_argv.debug,
             releaseStamp: context.releaseVersion,
-            library: new packages.Library(context.packageSearchOptions)
+            library: context.library
           }
         });
       }
@@ -868,9 +868,8 @@ Fiber(function () {
 
       var testPackages;
       if (_.isEmpty(argv._)) {
-        testPackages = _.keys((new packages.Library(context.packageSearchOptions)).list());
+        testPackages = _.keys(context.library.list());
       } else {
-        context.packageSearchOptions.preloadedPackages = {};
         testPackages = _.map(argv._, function (p) {
           // If it's a package name, the bundler will resolve it using
           // context.packageSearchOptions later.
@@ -882,8 +881,7 @@ Fiber(function () {
           // have a trailing slash.
           var packageDir = path.resolve(p);
           var packageName = path.basename(packageDir);
-          context.packageSearchOptions.preloadedPackages[packageName] =
-            packages.loadFromDir(packageName, packageDir);
+          context.library.preload(packageName, packageDir);
           return packageName;
         });
       }
@@ -894,7 +892,7 @@ Fiber(function () {
       // on each other.
       //
       // Note: context.appDir now is DIFFERENT from
-      // bundleOptions.packageSearchOptions.appDir: we are bundling the test
+      // bundleOptions.library.appDir: we are bundling the test
       // runner app, but finding app packages from the current app (if any).
       context.appDir = files.mkdtemp('meteor-test-run');
       files.cp_r(path.join(__dirname, 'test-runner-app'), context.appDir);
@@ -911,7 +909,7 @@ Fiber(function () {
           testPackages: testPackages,
           minify: new_argv.production,
           releaseStamp: context.releaseVersion,
-          library: new packages.Library(context.packageSearchOptions)
+          library: context.library
         }, {
           site: new_argv.deploy,
           settings: new_argv.settings && runner.getSettings(new_argv.settings)
@@ -989,7 +987,7 @@ Fiber(function () {
     }
     // dev bundle is downloaded by the wrapper script. We just need to install
     // NPM dependencies.
-    _.each((new Packages.Library(context.packageSearchOptions)).list(), function (p) {
+    _.each(context.library.list(), function (p) {
       p.installNpmDependencies();
     });
     process.exit(0);
diff --git a/tools/packages.js b/tools/packages.js
index 44d23eef5c..e99d7507a9 100644
--- a/tools/packages.js
+++ b/tools/packages.js
@@ -31,12 +31,26 @@ var fs = require('fs');
 // XXX XXX as implemented, it reads the environment and the current
 // directory. It shouldn't do that. Those should ultimately be ctor
 // arguments or something.
-var Library = function (packageSearchOptions) {
+var Library = function (options) {
   var self = this;
-  self.packageSearchOptions = packageSearchOptions || {};
+  options = options || {};
+
+  self.preloadedPackages = {};
+  self.releaseManifest = options.releaseManifest;
+  self.appDir = options.appDir;
 };
 
 _.extend(Library.prototype, {
+  // Temporarily add a package to the library (or override a package
+  // that actually exists in the library.) `packageName` is the name
+  // to use for the package and `packageDir` is the directory that
+  // contains its source.
+  preload: function (packageName, packageDir) {
+    var self = this;
+    self.preloadedPackages[packageName] =
+      packages.loadFromDir(packageName, packageDir);
+  },
+
   // get a package by name. also maps package objects to themselves.
   // load order is:
   // - APP_DIR/packages
@@ -48,16 +62,15 @@ _.extend(Library.prototype, {
     if (name instanceof Package)
       return name;
     if (!(name in loadedPackages)) {
-      if (self.packageSearchOptions.preloadedPackages &&
-          name in self.packageSearchOptions.preloadedPackages) {
-        loadedPackages[name] = self.packageSearchOptions.preloadedPackages[name];
+      if (self.preloadedPackages && name in self.preloadedPackages) {
+        loadedPackages[name] = self.preloadedPackages[name];
       } else {
         var pkg = new Package;
         if (pkg.initFromLocalPackages(name, self)) {
           loadedPackages[name] = pkg;
-        } else if (self.packageSearchOptions.releaseManifest) {
+        } else if (self.releaseManifest) {
           pkg.initFromWarehouse(
-            name, self.packageSearchOptions.releaseManifest.packages[name]);
+            name, self.releaseManifest.packages[name]);
           loadedPackages[name] = pkg;
         }
       }
@@ -92,8 +105,8 @@ _.extend(Library.prototype, {
       });
     });
 
-    if (self.packageSearchOptions.releaseManifest) {
-      _.each(self.packageSearchOptions.releaseManifest.packages, function(version, name) {
+    if (self.releaseManifest) {
+      _.each(self.releaseManifest.packages, function(version, name) {
         // don't even look for packages if they've already been
         // overridden (though this `if` isn't necessary for
         // correctness, since `packages.get` looks for packages in the
@@ -126,8 +139,8 @@ _.extend(Library.prototype, {
 
     // If we're running from an app (as opposed to a global-level "meteor
     // test-packages"), use app packages.
-    if (self.packageSearchOptions.appDir)
-      packageDirs.push(path.join(self.packageSearchOptions.appDir, 'packages'));
+    if (self.appDir)
+      packageDirs.push(path.join(self.appDir, 'packages'));
 
     // Next, search $PACKAGE_DIRS.
     if (process.env.PACKAGE_DIRS)
diff --git a/tools/run.js b/tools/run.js
index 7ef4b2d23c..b71c56c12e 100644
--- a/tools/run.js
+++ b/tools/run.js
@@ -635,7 +635,7 @@ exports.run = function (context, options) {
     minify: options.minify,
     testPackages: options.testPackages,
     releaseStamp: context.releaseVersion,
-    library: new packages.Library(context.packageSearchOptions)
+    library: context.library
   };
 
   var start_watching = function () {