diff --git a/tools/commands.js b/tools/commands.js
index 4e42276acb..5cc58ced94 100644
--- a/tools/commands.js
+++ b/tools/commands.js
@@ -1409,7 +1409,7 @@ main.registerCommand({
     browserstack: options.browserstack
   };
 
- return selftest.runTests({
+  return selftest.runTests({
     onlyChanged: options.changed,
     offline: offline,
     includeSlowTests: options.slow,
diff --git a/tools/config.js b/tools/config.js
index d34b3a9e06..916a01376b 100644
--- a/tools/config.js
+++ b/tools/config.js
@@ -161,22 +161,24 @@ _.extend(exports, {
     if (!serverUrl) serverUrl = self.getPackageServerUrl();
     var serLen = serverUrl.length;
 
-    // Chop off http:// and https://.
-    serverUrl = serverUrl.replace(/^\https:/, '');
-    serverUrl = serverUrl.replace(/^\http:/, '');
-    serverUrl = serverUrl.slice(2, serLen);
+    // Chop off http:// and https:// and trailing slashes.
+    serverUrl = serverUrl.replace(/^\https:\/\//, '');
+    serverUrl = serverUrl.replace(/^\http:\/\//, '');
+    serverUrl = serverUrl.replace(/\/+$/, '');
 
     // Chop off meteor.com.
-    serverUrl = serverUrl.replace(/meteor\.com/, '');
+    serverUrl = serverUrl.replace(/\.meteor\.com$/, '');
+
+    // Replace other weird stuff with X.
+    serverUrl = serverUrl.replace(/[^a-zA-Z0-9.:-]/g, 'X');
 
     // Should look like 'packages.data.json' in the default case
     // (test-packages.data.json before 0.9.0).
-    return serverUrl + "data.json";
+    return serverUrl + ".data.json";
   },
 
   getPackageStorage: function() {
     var self = this;
-    var serverFile = self.getPackageServerUrl() + ".data.json";
     return path.join(tropohouse.default.root,
                      "package-metadata", "v1",
                      self.getLocalPackageCacheFilename());
diff --git a/tools/selftest.js b/tools/selftest.js
index 6290edd78f..0e55c8604e 100644
--- a/tools/selftest.js
+++ b/tools/selftest.js
@@ -578,9 +578,9 @@ _.extend(Sandbox.prototype, {
   // releases containing that tool only (and no packages).
   //
   // packageServerUrl indicates which package server we think we are using. Use
-  // the default, if we do not pass this in -- which means that if you
-  // initialize a warehouse w/o specifying the packageServerUrl and *then* set a
-  // new PACKAGE_SERVER_URL environment variable, you will be sad.
+  // the default, if we do not pass this in; you should pass it in any case that
+  // you will be specifying $METEOR_PACKAGE_SERVER_URL in the environment of a
+  // command you are running in this sandbox.
   _makeWarehouse: function (releases, packageServerUrl) {
     var self = this;
     files.mkdir_p(path.join(self.warehouse, 'packages'), 0755);