diff --git a/.travis.yml b/.travis.yml
index 0cf166baac..7aadac0a75 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,10 @@ cache:
   directories:
     - ".meteor"
     - ".babel-cache"
-script: TEST_PACKAGES_EXCLUDE="less" phantom=false ./packages/test-in-console/run.sh
+script:
+  - export TEST_PACKAGES_EXCLUDE="less"
+  - export phantom=false
+  - travis_retry ./packages/test-in-console/run.sh
 sudo: false
 env:
   - CXX=g++-4.8
diff --git a/History.md b/History.md
index afb011f516..69ebe569e1 100644
--- a/History.md
+++ b/History.md
@@ -5,7 +5,15 @@
 * Cordova has been updated from version 7 to 9. We recommend that you test
   your features that are taking advantage of Cordova plugins to be sure
   they are still working as expected.
+  
+* Because MongoDB since 3.4 no longer supports 32-bit Windows, Meteor 1.10 has 
+  also dropped support for 32-bit Windows. In other words, Meteor 1.10 supports
+  64-bit Mac, Windows 64-bit, and Linux 64-bit.
 
+### Migration Steps
+N/A
+
+### Changes
 * The version of MongoDB used by Meteor in development has been updated
   from 4.0.6 to 4.2.1, and the `mongodb` driver package has been updated
   from 3.2.7 to 3.4.0, thanks to [@klaussner](https://github.com/klaussner).
@@ -73,6 +81,11 @@ N/A
     * Updated V8 to [release v7.8](https://v8.dev/blog/v8-release-78) which includes improvements in performance, for example, object destructuring now is as fast as the equivalent variable assignment.
   * [12.15.0](https://nodejs.org/en/blog/release/v12.15.0/)
 
+* `cursor.observeChanges` now accepts a second options argument.
+  If your observer functions do not mutate the passed arguments, you can specify
+  `{ nonMutatingCallbacks: true }`, which improves performance by reducing
+  the amount of data copies.
+
 ## v1.9, 2020-01-09
 
 ### Breaking changes
diff --git a/meteor b/meteor
index c1280507c7..0f3b530601 100755
--- a/meteor
+++ b/meteor
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-BUNDLE_VERSION=12.16.1.3
+BUNDLE_VERSION=12.16.1.4
 
 # OS Check. Put here because here is where we download the precompiled
 # bundles that are arch specific.
diff --git a/packages/accounts-base/accounts_server.js b/packages/accounts-base/accounts_server.js
index fc0d35a89d..afed16aba8 100644
--- a/packages/accounts-base/accounts_server.js
+++ b/packages/accounts-base/accounts_server.js
@@ -895,7 +895,7 @@ export class AccountsServer extends AccountsCommon {
           // The onClose callback for the connection takes care of
           // cleaning up the observe handle and any other state we have
           // lying around.
-        });
+        }, { nonMutatingCallbacks: true });
 
         // If the user ran another login or logout command we were waiting for the
         // defer or added to fire (ie, another call to _setLoginToken occurred),
diff --git a/packages/accounts-base/package.js b/packages/accounts-base/package.js
index 0ea2c05a6c..5e023cb059 100644
--- a/packages/accounts-base/package.js
+++ b/packages/accounts-base/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "A user account system",
-  version: "1.5.0",
+  version: "1.6.0-beta110.8",
 });
 
 Package.onUse(api => {
diff --git a/packages/accounts-oauth/package.js b/packages/accounts-oauth/package.js
index 484fe7e125..1b21c89251 100644
--- a/packages/accounts-oauth/package.js
+++ b/packages/accounts-oauth/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Common code for OAuth-based login services",
-  version: "1.1.16",
+  version: "1.2.0-beta110.8",
 });
 
 Package.onUse(api => {
diff --git a/packages/accounts-password/package.js b/packages/accounts-password/package.js
index a390f09660..18190e2379 100644
--- a/packages/accounts-password/package.js
+++ b/packages/accounts-password/package.js
@@ -5,7 +5,7 @@ Package.describe({
   // 2.2.x in the future. The version was also bumped to 2.0.0 temporarily
   // during the Meteor 1.5.1 release process, so versions 2.0.0-beta.2
   // through -beta.5 and -rc.0 have already been published.
-  version: "1.5.3"
+  version: "1.6.0-beta110.8"
 });
 
 Package.onUse(api => {
diff --git a/packages/appcache/appcache-server.js b/packages/appcache/appcache-server.js
index ca4f97eded..52613b83ae 100755
--- a/packages/appcache/appcache-server.js
+++ b/packages/appcache/appcache-server.js
@@ -261,10 +261,12 @@ function eachResource({
 }
 
 function sizeCheck() {
-  const sizes = [ // Check size of each known architecture independently.
+  const RESOURCE_SIZE_LIMIT = 5 * 1024 * 1024; // 5MB
+  const largeSizes = [ // Check size of each known architecture independently.
     "web.browser",
     "web.browser.legacy",
-  ].reduce((filt, arch) => {
+  ].filter((arch) => !!WebApp.clientPrograms[arch])
+  .map((arch) => {
     let totalSize = 0;
 
     WebApp.clientPrograms[arch].manifest.forEach(resource => {
@@ -275,22 +277,21 @@ function sizeCheck() {
       }
     });
 
-    if (totalSize > 5 * 1024 * 1024) {
-      filt.push({
-        arch,
-        size: totalSize
-      });
+    return {
+      arch,
+      size: totalSize,
     }
-    return filt;
-  }, []);
-  if (sizes.length > 0) {
+  })
+  .filter(({ size }) => size > RESOURCE_SIZE_LIMIT);
+
+  if (largeSizes.length > 0) {
     Meteor._debug([
       "** You are using the appcache package, but the size of",
       "** one or more of your cached resources is larger than",
       "** the recommended maximum size of 5MB which may break",
       "** your app in some browsers!",
       "** ",
-      ...sizes.map(data => `** ${data.arch}: ${(data.size / 1024 / 1024).toFixed(1)}MB`),
+      ...largeSizes.map(data => `** ${data.arch}: ${(data.size / 1024 / 1024).toFixed(1)}MB`),
       "** ",
       "** See http://docs.meteor.com/#appcache for more",
       "** information and fixes."
diff --git a/packages/boilerplate-generator/package.js b/packages/boilerplate-generator/package.js
index 0e8ebfef77..66734ecdcf 100644
--- a/packages/boilerplate-generator/package.js
+++ b/packages/boilerplate-generator/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Generates the boilerplate html from program's manifest",
-  version: '1.6.0'
+  version: '1.7.0-beta110.8'
 });
 
 Npm.depends({
diff --git a/packages/facebook-oauth/package.js b/packages/facebook-oauth/package.js
index 0ed950e060..57ce8b34f6 100644
--- a/packages/facebook-oauth/package.js
+++ b/packages/facebook-oauth/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Facebook OAuth flow",
-  version: "1.7.0"
+  version: "1.7.0-beta110.8"
 });
 
 Package.onUse(api => {
diff --git a/packages/launch-screen/package.js b/packages/launch-screen/package.js
index 52d688d784..2381face64 100644
--- a/packages/launch-screen/package.js
+++ b/packages/launch-screen/package.js
@@ -6,7 +6,7 @@ Package.describe({
   // between such packages and the build tool.
   name: 'launch-screen',
   summary: 'Default and customizable launch screen on mobile.',
-  version: '1.2.0'
+  version: '1.2.0-beta110.8'
 });
 
 Cordova.depends({
diff --git a/packages/meteor-tool/package.js b/packages/meteor-tool/package.js
index 3f8c982f8e..38b2b1f25f 100644
--- a/packages/meteor-tool/package.js
+++ b/packages/meteor-tool/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "The Meteor command-line tool",
-  version: '1.9.2'
+  version: '1.10.0-beta.8'
 });
 
 Package.includeTool();
diff --git a/packages/minimongo/local_collection.js b/packages/minimongo/local_collection.js
index 5ea83843e0..e767137089 100644
--- a/packages/minimongo/local_collection.js
+++ b/packages/minimongo/local_collection.js
@@ -669,17 +669,18 @@ LocalCollection._CachingChangeObserver = class _CachingChangeObserver {
       this.docs = new OrderedDict(MongoID.idStringify);
       this.applyChange = {
         addedBefore: (id, fields, before) => {
-          const doc = EJSON.clone(fields);
+          // Take a shallow copy since the top-level properties can be changed
+          const doc = { ...fields };
 
           doc._id = id;
 
           if (callbacks.addedBefore) {
-            callbacks.addedBefore.call(this, id, fields, before);
+            callbacks.addedBefore.call(this, id, EJSON.clone(fields), before);
           }
 
           // This line triggers if we provide added with movedBefore.
           if (callbacks.added) {
-            callbacks.added.call(this, id, fields);
+            callbacks.added.call(this, id, EJSON.clone(fields));
           }
 
           // XXX could `before` be a falsy ID?  Technically
@@ -701,10 +702,11 @@ LocalCollection._CachingChangeObserver = class _CachingChangeObserver {
       this.docs = new LocalCollection._IdMap;
       this.applyChange = {
         added: (id, fields) => {
-          const doc = EJSON.clone(fields);
+          // Take a shallow copy since the top-level properties can be changed
+          const doc = { ...fields };
 
           if (callbacks.added) {
-            callbacks.added.call(this, id, fields);
+            callbacks.added.call(this, id, EJSON.clone(fields));
           }
 
           doc._id = id;
@@ -1330,7 +1332,12 @@ LocalCollection._observeFromObserveChanges = (cursor, observeCallbacks) => {
     callbacks: observeChangesCallbacks
   });
 
-  const handle = cursor.observeChanges(changeObserver.applyChange);
+  // CachingChangeObserver clones all received input on its callbacks
+  // So we can mark it as safe to reduce the ejson clones.
+  // This is tested by the `mongo-livedata - (extended) scribbling` tests
+  changeObserver.applyChange._fromObserve = true;
+  const handle = cursor.observeChanges(changeObserver.applyChange,
+    { nonMutatingCallbacks: true });
 
   suppressed = false;
 
diff --git a/packages/minimongo/package.js b/packages/minimongo/package.js
index 047682d2a7..f5798f3676 100644
--- a/packages/minimongo/package.js
+++ b/packages/minimongo/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Meteor's client-side datastore: a port of MongoDB to Javascript",
-  version: '1.4.5'
+  version: '1.5.0-beta110.8'
 });
 
 Package.onUse(api => {
diff --git a/packages/mobile-experience/package.js b/packages/mobile-experience/package.js
index 43da7982c3..b2f974162a 100644
--- a/packages/mobile-experience/package.js
+++ b/packages/mobile-experience/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   name: 'mobile-experience',
-  version: '1.1.0',
+  version: '1.1.0-beta110.8',
   summary: 'Packages for a great mobile user experience',
   documentation: 'README.md'
 });
diff --git a/packages/mobile-status-bar/package.js b/packages/mobile-status-bar/package.js
index 1b7aa76127..bb5e13cd60 100644
--- a/packages/mobile-status-bar/package.js
+++ b/packages/mobile-status-bar/package.js
@@ -1,7 +1,7 @@
 Package.describe({
   name: 'mobile-status-bar',
   summary: "Good defaults for the mobile status bar",
-  version: "1.1.0"
+  version: "1.1.0-beta110.8"
 });
 
 Cordova.depends({
diff --git a/packages/mongo/collection.js b/packages/mongo/collection.js
index a610481ba6..30d6c82da7 100644
--- a/packages/mongo/collection.js
+++ b/packages/mongo/collection.js
@@ -372,7 +372,10 @@ Object.assign(Mongo.Collection, {
       removed: function (id) {
         sub.removed(collection, id);
       }
-    });
+    },
+    // Publications don't mutate the documents
+    // This is tested by the `livedata - publish callbacks clone` test
+    { nonMutatingCallbacks: true });
 
     // We don't call sub.ready() here: it gets called in livedata_server, after
     // possibly calling _publishCursor on multiple returned cursors.
diff --git a/packages/mongo/mongo_driver.js b/packages/mongo/mongo_driver.js
index 4be68220e6..40a36b42bf 100644
--- a/packages/mongo/mongo_driver.js
+++ b/packages/mongo/mongo_driver.js
@@ -918,7 +918,7 @@ Cursor.prototype.observe = function (callbacks) {
   return LocalCollection._observeFromObserveChanges(self, callbacks);
 };
 
-Cursor.prototype.observeChanges = function (callbacks) {
+Cursor.prototype.observeChanges = function (callbacks, options = {}) {
   var self = this;
   var methods = [
     'addedAt',
@@ -931,8 +931,8 @@ Cursor.prototype.observeChanges = function (callbacks) {
   ];
   var ordered = LocalCollection._observeChangesCallbacksAreOrdered(callbacks);
 
-  // XXX: Can we find out if callbacks are from observe?
-  var exceptionName = ' observe/observeChanges callback';
+  let exceptionName = callbacks._fromObserve ? 'observe' : 'observeChanges';
+  exceptionName += ' callback';
   methods.forEach(function (method) {
     if (callbacks[method] && typeof callbacks[method] == "function") {
       callbacks[method] = Meteor.bindEnvironment(callbacks[method], method + exceptionName);
@@ -940,7 +940,7 @@ Cursor.prototype.observeChanges = function (callbacks) {
   });
 
   return self._mongo._observeChanges(
-    self._cursorDescription, ordered, callbacks);
+    self._cursorDescription, ordered, callbacks, options.nonMutatingCallbacks);
 };
 
 MongoConnection.prototype._createSynchronousCursor = function(
@@ -1241,7 +1241,7 @@ MongoConnection.prototype.tail = function (cursorDescription, docCallback, timeo
 };
 
 MongoConnection.prototype._observeChanges = function (
-    cursorDescription, ordered, callbacks) {
+    cursorDescription, ordered, callbacks, nonMutatingCallbacks) {
   var self = this;
 
   if (cursorDescription.options.tailable) {
@@ -1282,7 +1282,10 @@ MongoConnection.prototype._observeChanges = function (
     }
   });
 
-  var observeHandle = new ObserveHandle(multiplexer, callbacks);
+  var observeHandle = new ObserveHandle(multiplexer,
+    callbacks,
+    nonMutatingCallbacks,
+  );
 
   if (firstHandle) {
     var matcher, sorter;
diff --git a/packages/mongo/mongo_livedata_tests.js b/packages/mongo/mongo_livedata_tests.js
index 30ea3c10e1..8f77d1c822 100644
--- a/packages/mongo/mongo_livedata_tests.js
+++ b/packages/mongo/mongo_livedata_tests.js
@@ -560,6 +560,80 @@ Tinytest.addAsync("mongo-livedata - scribbling, " + idGeneration, function (test
   onComplete();
 });
 
+if (Meteor.isServer) {
+  Tinytest.addAsync("mongo-livedata - extended scribbling, " + idGeneration, function (test, onComplete) {
+    function error() {
+      throw new Meteor.Error('unsafe object mutation');
+    }
+    
+    const denyModifications = {
+      get(target, key) {
+        const type = Object.prototype.toString.call(target[key]);
+        if (type === '[object Object]' || type === '[object Array]') {
+          return freeze(target[key]);
+        } else {
+          return target[key];
+        }
+      },
+      set: error,
+      deleteProperty: error,
+      defineProperty: error,
+    };
+    
+    // Object.freeze only throws in silent mode
+    // So we make our own version that always throws.
+    function freeze(obj) {
+      return new Proxy(obj, denyModifications);
+    }
+
+    const origApplyCallback = ObserveMultiplexer.prototype._applyCallback;
+    ObserveMultiplexer.prototype._applyCallback = function(callback, args) {
+      // Make sure that if anything touches the original object, this will throw
+      return origApplyCallback.call(this, callback, freeze(args));
+    }
+    
+    const run = test.runId();
+    const coll = new Mongo.Collection(`livedata_test_scribble_collection_${run}`, collectionOptions);
+    const expectMutatable = (o) => {
+      try {
+        o.a[0].c = 3;
+      } catch (error) {
+        test.fail();
+      }
+    }
+    const expectNotMutatable = (o) => {
+      try {
+        o.a[0].c = 3;
+        test.fail();
+      } catch (error) {}
+    }
+    const handle = coll.find({run}).observe({
+      addedAt: expectMutatable,
+      changedAt: function(id, o) {
+        expectMutatable(o);
+      }
+    });
+
+    const handle2 = coll.find({run}).observeChanges({
+      added: expectNotMutatable,
+      changed: function(id, o) {
+        expectNotMutatable(o);
+      }
+    }, { nonMutatingCallbacks: true });
+
+    runInFence(function () {
+      coll.insert({run, a: [ {c: 1} ]});
+      coll.update({run}, { $set: { 'a.0.c': 2 } });
+    });
+ 
+    handle.stop();
+    handle2.stop();
+
+    ObserveMultiplexer.prototype._applyCallback = origApplyCallback;
+    onComplete();
+  });
+}
+
 Tinytest.addAsync("mongo-livedata - stop handle in callback, " + idGeneration, function (test, onComplete) {
   var run = Random.id();
   var coll;
diff --git a/packages/mongo/observe_multiplex.js b/packages/mongo/observe_multiplex.js
index aa766bc07f..6e8f9349f6 100644
--- a/packages/mongo/observe_multiplex.js
+++ b/packages/mongo/observe_multiplex.js
@@ -155,11 +155,7 @@ _.extend(ObserveMultiplexer.prototype, {
         return;
 
       // First, apply the change to the cache.
-      // XXX We could make applyChange callbacks promise not to hang on to any
-      // state from their arguments (assuming that their supplied callbacks
-      // don't) and skip this clone. Currently 'changed' hangs on to state
-      // though.
-      self._cache.applyChange[callbackName].apply(null, EJSON.clone(args));
+      self._cache.applyChange[callbackName].apply(null, args);
 
       // If we haven't finished the initial adds, then we should only be getting
       // adds.
@@ -179,7 +175,8 @@ _.extend(ObserveMultiplexer.prototype, {
           return;
         var callback = handle['_' + callbackName];
         // clone arguments so that callbacks can mutate their arguments
-        callback && callback.apply(null, EJSON.clone(args));
+        callback && callback.apply(null,
+          handle.nonMutatingCallbacks ? args : EJSON.clone(args));
       });
     });
   },
@@ -199,8 +196,8 @@ _.extend(ObserveMultiplexer.prototype, {
     self._cache.docs.forEach(function (doc, id) {
       if (!_.has(self._handles, handle._id))
         throw Error("handle got removed before sending initial adds!");
-      var fields = EJSON.clone(doc);
-      delete fields._id;
+      const { _id, ...fields } = handle.nonMutatingCallbacks ? doc
+        : EJSON.clone(doc);
       if (self._ordered)
         add(id, fields, null); // we're going in order, so add at end
       else
@@ -211,7 +208,9 @@ _.extend(ObserveMultiplexer.prototype, {
 
 
 var nextObserveHandleId = 1;
-ObserveHandle = function (multiplexer, callbacks) {
+
+// When the callbacks do not mutate the arguments, we can skip a lot of data clones
+ObserveHandle = function (multiplexer, callbacks, nonMutatingCallbacks = false) {
   var self = this;
   // The end user is only supposed to call stop().  The other fields are
   // accessible to the multiplexer, though.
@@ -231,6 +230,7 @@ ObserveHandle = function (multiplexer, callbacks) {
   });
   self._stopped = false;
   self._id = nextObserveHandleId++;
+  self.nonMutatingCallbacks = nonMutatingCallbacks;
 };
 ObserveHandle.prototype.stop = function () {
   var self = this;
diff --git a/packages/mongo/package.js b/packages/mongo/package.js
index c05b92ced7..64f97c96f4 100644
--- a/packages/mongo/package.js
+++ b/packages/mongo/package.js
@@ -9,7 +9,7 @@
 
 Package.describe({
   summary: "Adaptor for using MongoDB and Minimongo over DDP",
-  version: '1.8.1'
+  version: '1.9.0-beta110.8'
 });
 
 Npm.depends({
@@ -71,6 +71,7 @@ Package.onUse(function (api) {
   api.export('MongoInternals', 'server');
 
   api.export("Mongo");
+  api.export('ObserveMultiplexer', 'server', {testOnly: true});
 
   api.addFiles(['mongo_driver.js', 'oplog_tailing.js',
                  'observe_multiplex.js', 'doc_fetcher.js',
diff --git a/packages/npm-mongo/package.js b/packages/npm-mongo/package.js
index 236c024f36..169a9239d4 100644
--- a/packages/npm-mongo/package.js
+++ b/packages/npm-mongo/package.js
@@ -3,7 +3,7 @@
 
 Package.describe({
   summary: "Wrapper around the mongo npm package",
-  version: "3.5.0",
+  version: "3.5.0-beta110.8",
   documentation: null
 });
 
diff --git a/packages/oauth/package.js b/packages/oauth/package.js
index 54f13f1767..2a739b3f07 100644
--- a/packages/oauth/package.js
+++ b/packages/oauth/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Common code for OAuth-based services",
-  version: "1.2.8"
+  version: "1.3.0-beta110.8"
 });
 
 Package.onUse(api => {
diff --git a/packages/oauth1/package.js b/packages/oauth1/package.js
index 11dc87fc7d..73bed1a5a7 100644
--- a/packages/oauth1/package.js
+++ b/packages/oauth1/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Common code for OAuth1-based login services",
-  version: "1.2.2",
+  version: "1.3.0-beta110.8",
 });
 
 Package.onUse(api => {
diff --git a/packages/webapp/package.js b/packages/webapp/package.js
index 68af50c1db..30844811aa 100644
--- a/packages/webapp/package.js
+++ b/packages/webapp/package.js
@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Serves a Meteor app over HTTP",
-  version: '1.8.2'
+  version: '1.9.0-beta110.8'
 });
 
 Npm.depends({"basic-auth-connect": "1.0.0",
@@ -20,9 +20,9 @@ Npm.strip({
 });
 
 Cordova.depends({
-  'cordova-plugin-whitelist': '1.3.3',
-  'cordova-plugin-wkwebview-engine': '1.1.4',
-  'cordova-plugin-meteor-webapp': '1.7.0'
+  'cordova-plugin-whitelist': '1.3.4',
+  'cordova-plugin-wkwebview-engine': '1.2.1',
+  'cordova-plugin-meteor-webapp': '1.8.0'
 });
 
 Package.onUse(function (api) {
diff --git a/packages/webapp/webapp_server.js b/packages/webapp/webapp_server.js
index 12ba0cf505..2cc63fa21c 100644
--- a/packages/webapp/webapp_server.js
+++ b/packages/webapp/webapp_server.js
@@ -404,6 +404,12 @@ WebAppInternals.staticFilesMiddleware = async function (
     identifyBrowser(req.headers["user-agent"]),
   );
 
+  if (! hasOwn.call(WebApp.clientPrograms, arch)) {
+    // We could come here in case we run with some architectures excluded
+    next();
+    return;
+  }
+
   // If pauseClient(arch) has been called, program.paused will be a
   // Promise that will be resolved when the program is unpaused.
   const program = WebApp.clientPrograms[arch];
@@ -987,6 +993,19 @@ function runWebAppServer() {
         request.browser,
       );
 
+      if (! hasOwn.call(WebApp.clientPrograms, arch)) {
+        // We could come here in case we run with some architectures excluded
+        headers['Cache-Control'] = 'no-cache';
+        res.writeHead(404, headers);
+        if (Meteor.isDevelopment) {
+          res.end(`No client program found for the ${arch} architecture.`);
+        } else {
+          // Safety net, but this branch should not be possible.
+          res.end("404 Not Found");
+        }
+        return;
+      }
+
       // If pauseClient(arch) has been called, program.paused will be a
       // Promise that will be resolved when the program is unpaused.
       await WebApp.clientPrograms[arch].paused;
diff --git a/scripts/admin/copy-dev-bundle-from-jenkins.sh b/scripts/admin/copy-dev-bundle-from-jenkins.sh
index af7cb75829..ab6bfdb13a 100755
--- a/scripts/admin/copy-dev-bundle-from-jenkins.sh
+++ b/scripts/admin/copy-dev-bundle-from-jenkins.sh
@@ -39,7 +39,7 @@ echo Found build $DIRNAME
 trap "echo Found surprising number of tarballs." EXIT
 # Check to make sure the proper number of each kind of file is there.
 aws s3 ls s3://com.meteor.jenkins/$DIRNAME/ | \
-  perl -nle 'if (/\.tar\.gz/) { ++$TAR } else { die "something weird" }  END { exit !($TAR == 4) }'
+  perl -nle 'if (/\.tar\.gz/) { ++$TAR } else { die "something weird" }  END { exit !($TAR == 3) }'
 
 trap - EXIT
 
diff --git a/scripts/admin/meteor-release-experimental.json b/scripts/admin/meteor-release-experimental.json
index 5147a9be41..c5eb9cf44a 100644
--- a/scripts/admin/meteor-release-experimental.json
+++ b/scripts/admin/meteor-release-experimental.json
@@ -1,6 +1,6 @@
 {
   "track": "METEOR",
-  "version": "1.9.2-rc.1",
+  "version": "1.10-beta.8",
   "recommended": false,
   "official": false,
   "description": "Meteor"
diff --git a/scripts/generate-dev-bundle.ps1 b/scripts/generate-dev-bundle.ps1
index aa9f36b0bf..d1f239f864 100644
--- a/scripts/generate-dev-bundle.ps1
+++ b/scripts/generate-dev-bundle.ps1
@@ -72,9 +72,6 @@ Function Add-7ZipTool {
   $webclient.DownloadFile("http://www.7-zip.org/a/7z1604-extra.7z", $extraArchive)
 
   $pathToExtract = 'x64/7za.exe'
-  if ($PLATFORM -eq "windows_x86") {
-    $pathToExtract = '7za.exe'
-  }
 
   Write-Host 'Placing 7za.exe from extra.7z in \bin...' -ForegroundColor Magenta
   & "$system7zip" e $extraArchive -o"$dirTemp" $pathToExtract | Out-Null
@@ -118,11 +115,7 @@ Function Add-NodeAndNpm {
     $nodeUrlBase = 'https://nodejs.org/dist'
   }
 
-  if ($PLATFORM -eq "windows_x86") {
-    $nodeArchitecture = 'win-x86'
-  } else {
-    $nodeArchitecture = 'win-x64'
-  }
+  $nodeArchitecture = 'win-x64'
 
   # Various variables which are used as part of directory paths and
   # inside Node release and header archives.
@@ -231,7 +224,6 @@ Function Add-Mongo {
   # Mongo >= 3.4 no longer supports 32-bit (x86) architectures, so we package
   # the latest 3.2 version of Mongo for those builds and >= 3.4 for x64.
   $mongo_filenames = @{
-    windows_x86 = "mongodb-win32-i386-${MONGO_VERSION_32BIT}"
     windows_x64 = "mongodb-win32-x86_64-2012plus-${MONGO_VERSION_64BIT}"
   }
 
diff --git a/tools/cli/commands.js b/tools/cli/commands.js
index 222e713465..d43dfc5ddd 100644
--- a/tools/cli/commands.js
+++ b/tools/cli/commands.js
@@ -162,6 +162,16 @@ export function parseRunTargets(targets) {
   });
 };
 
+const excludableWebArchs = ['web.browser', 'web.browser.legacy', 'web.cordova'];
+function filterWebArchs(webArchs, excludeArchsOption) {
+  if (excludeArchsOption) {
+    const excludeArchs = excludeArchsOption.trim().split(/\s*,\s*/)
+      .filter(arch => excludableWebArchs.includes(arch));
+    webArchs = webArchs.filter(arch => !excludeArchs.includes(arch));
+  }
+  return webArchs;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // options that act like commands
 ///////////////////////////////////////////////////////////////////////////////
@@ -318,7 +328,8 @@ var runCommandOptions = {
     // Allow the version solver to make breaking changes to the versions
     // of top-level dependencies.
     'allow-incompatible-update': { type: Boolean },
-    'extra-packages': { type: String }
+    'extra-packages': { type: String },
+    'exclude-archs': { type: String }
   },
   catalogRefresh: new catalog.Refresh.Never()
 };
@@ -399,6 +410,7 @@ function doRunCommand(options) {
       webArchs.push("web.cordova");
     }
   }
+  webArchs = filterWebArchs(webArchs, options['exclude-archs']);
 
   let cordovaRunner;
   if (!_.isEmpty(runTargets)) {
@@ -1635,7 +1647,9 @@ testCommandOptions = {
     // For 'test-packages': Run in "full app" mode
     'full-app': { type: Boolean, 'default': false },
 
-    'extra-packages': { type: String }
+    'extra-packages': { type: String },
+
+    'exclude-archs': { type: String }
   }
 };
 
@@ -1978,6 +1992,11 @@ var runTestAppForPackages = function (projectContext, options) {
     minifyMode: options.production ? 'production' : 'development'
   };
   buildOptions.buildMode = "test";
+  let webArchs = projectContext.platformList.getWebArchs();
+  if (options.cordovaRunner) {
+    webArchs.push("web.cordova");
+  }
+  buildOptions.webArchs = filterWebArchs(webArchs, options['exclude-archs']);
 
   if (options.deploy) {
     // Run the constraint solver and build local packages.
diff --git a/tools/cli/dev-bundle.js b/tools/cli/dev-bundle.js
index 9589dd9364..a89946e73e 100644
--- a/tools/cli/dev-bundle.js
+++ b/tools/cli/dev-bundle.js
@@ -189,10 +189,7 @@ function makeStatTest(method) {
 
 function getHostArch() {
   if (process.platform === "win32") {
-    if (process.arch === "x64") {
-      return "os.windows.x86_64";
-    }
-    return "os.windows.x86_32";
+    return "os.windows.x86_64";
   }
 
   if (process.platform === "linux") {
diff --git a/tools/cli/help.txt b/tools/cli/help.txt
index 300f04e704..e5b919d555 100644
--- a/tools/cli/help.txt
+++ b/tools/cli/help.txt
@@ -103,6 +103,9 @@ Options:
                    version constraints.
   --extra-packages Run with additional packages (comma separated, for example:
                    --extra-packages "package-name1, package-name2@1.2.3")
+  --exclude-archs  Don't create bundles for certain web architectures
+                  (comma separated, for example:
+                   --exclude-archs "web.browser.legacy, web.cordova")
 
 >>> debug
 Run the project with server-side debugging enabled.
@@ -713,6 +716,9 @@ Options:
   --driver-package  Name of the optional test driver package to use to run
                     tests and display results. For example:
                     --driver-package practicalmeteor:mocha
+  --exclude-archs   Don't create test bundles for certain web architectures
+                    (comma separated, for example:
+                    --exclude-archs "web.browser.legacy, web.cordova")
 
 >>> self-test
 Run tests of the 'meteor' tool.
diff --git a/tools/tests/apps/modules/package-lock.json b/tools/tests/apps/modules/package-lock.json
index 2351624583..0bfa075a4a 100644
--- a/tools/tests/apps/modules/package-lock.json
+++ b/tools/tests/apps/modules/package-lock.json
@@ -12,24 +12,123 @@
       }
     },
     "@babel/core": {
-      "version": "7.7.2",
-      "resolved": "https://registry.npmjs.org/@babel/core/-/core-7.7.2.tgz",
-      "integrity": "sha512-eeD7VEZKfhK1KUXGiyPFettgF3m513f8FoBSWiQ1xTvl1RAopLs42Wp9+Ze911I6H0N9lNqJMDgoZT7gHsipeQ==",
+      "version": "7.8.4",
+      "resolved": "https://registry.npmjs.org/@babel/core/-/core-7.8.4.tgz",
+      "integrity": "sha512-0LiLrB2PwrVI+a2/IEskBopDYSd8BCb3rOvH7D5tzoWd696TBEduBvuLVm4Nx6rltrLZqvI3MCalB2K2aVzQjA==",
       "requires": {
-        "@babel/code-frame": "^7.5.5",
-        "@babel/generator": "^7.7.2",
-        "@babel/helpers": "^7.7.0",
-        "@babel/parser": "^7.7.2",
-        "@babel/template": "^7.7.0",
-        "@babel/traverse": "^7.7.2",
-        "@babel/types": "^7.7.2",
+        "@babel/code-frame": "^7.8.3",
+        "@babel/generator": "^7.8.4",
+        "@babel/helpers": "^7.8.4",
+        "@babel/parser": "^7.8.4",
+        "@babel/template": "^7.8.3",
+        "@babel/traverse": "^7.8.4",
+        "@babel/types": "^7.8.3",
         "convert-source-map": "^1.7.0",
         "debug": "^4.1.0",
+        "gensync": "^1.0.0-beta.1",
         "json5": "^2.1.0",
         "lodash": "^4.17.13",
         "resolve": "^1.3.2",
         "semver": "^5.4.1",
         "source-map": "^0.5.0"
+      },
+      "dependencies": {
+        "@babel/code-frame": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.8.3.tgz",
+          "integrity": "sha512-a9gxpmdXtZEInkCSHUJDLHZVBgb1QS0jhss4cPP93EW7s+uC5bikET2twEF3KV+7rDblJcmNvTR7VJejqd2C2g==",
+          "requires": {
+            "@babel/highlight": "^7.8.3"
+          }
+        },
+        "@babel/generator": {
+          "version": "7.8.4",
+          "resolved": "https://registry.npmjs.org/@babel/generator/-/generator-7.8.4.tgz",
+          "integrity": "sha512-PwhclGdRpNAf3IxZb0YVuITPZmmrXz9zf6fH8lT4XbrmfQKr6ryBzhv593P5C6poJRciFCL/eHGW2NuGrgEyxA==",
+          "requires": {
+            "@babel/types": "^7.8.3",
+            "jsesc": "^2.5.1",
+            "lodash": "^4.17.13",
+            "source-map": "^0.5.0"
+          }
+        },
+        "@babel/helper-function-name": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/helper-function-name/-/helper-function-name-7.8.3.tgz",
+          "integrity": "sha512-BCxgX1BC2hD/oBlIFUgOCQDOPV8nSINxCwM3o93xP4P9Fq6aV5sgv2cOOITDMtCfQ+3PvHp3l689XZvAM9QyOA==",
+          "requires": {
+            "@babel/helper-get-function-arity": "^7.8.3",
+            "@babel/template": "^7.8.3",
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/helper-get-function-arity": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/helper-get-function-arity/-/helper-get-function-arity-7.8.3.tgz",
+          "integrity": "sha512-FVDR+Gd9iLjUMY1fzE2SR0IuaJToR4RkCDARVfsBBPSP53GEqSFjD8gNyxg246VUyc/ALRxFaAK8rVG7UT7xRA==",
+          "requires": {
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/helper-split-export-declaration": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.8.3.tgz",
+          "integrity": "sha512-3x3yOeyBhW851hroze7ElzdkeRXQYQbFIb7gLK1WQYsw2GWDay5gAJNw1sWJ0VFP6z5J1whqeXH/WCdCjZv6dA==",
+          "requires": {
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/highlight": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/highlight/-/highlight-7.8.3.tgz",
+          "integrity": "sha512-PX4y5xQUvy0fnEVHrYOarRPXVWafSjTW9T0Hab8gVIawpl2Sj0ORyrygANq+KjcNlSSTw0YCLSNA8OyZ1I4yEg==",
+          "requires": {
+            "chalk": "^2.0.0",
+            "esutils": "^2.0.2",
+            "js-tokens": "^4.0.0"
+          }
+        },
+        "@babel/parser": {
+          "version": "7.8.4",
+          "resolved": "https://registry.npmjs.org/@babel/parser/-/parser-7.8.4.tgz",
+          "integrity": "sha512-0fKu/QqildpXmPVaRBoXOlyBb3MC+J0A66x97qEfLOMkn3u6nfY5esWogQwi/K0BjASYy4DbnsEWnpNL6qT5Mw=="
+        },
+        "@babel/template": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/template/-/template-7.8.3.tgz",
+          "integrity": "sha512-04m87AcQgAFdvuoyiQ2kgELr2tV8B4fP/xJAVUL3Yb3bkNdMedD3d0rlSQr3PegP0cms3eHjl1F7PWlvWbU8FQ==",
+          "requires": {
+            "@babel/code-frame": "^7.8.3",
+            "@babel/parser": "^7.8.3",
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/traverse": {
+          "version": "7.8.4",
+          "resolved": "https://registry.npmjs.org/@babel/traverse/-/traverse-7.8.4.tgz",
+          "integrity": "sha512-NGLJPZwnVEyBPLI+bl9y9aSnxMhsKz42so7ApAv9D+b4vAFPpY013FTS9LdKxcABoIYFU52HcYga1pPlx454mg==",
+          "requires": {
+            "@babel/code-frame": "^7.8.3",
+            "@babel/generator": "^7.8.4",
+            "@babel/helper-function-name": "^7.8.3",
+            "@babel/helper-split-export-declaration": "^7.8.3",
+            "@babel/parser": "^7.8.4",
+            "@babel/types": "^7.8.3",
+            "debug": "^4.1.0",
+            "globals": "^11.1.0",
+            "lodash": "^4.17.13"
+          }
+        },
+        "@babel/types": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.8.3.tgz",
+          "integrity": "sha512-jBD+G8+LWpMBBWvVcdr4QysjUE4mU/syrhN17o1u3gx0/WzJB1kwiVZAXRtWbsIPOwW8pF/YJV5+nmetPzepXg==",
+          "requires": {
+            "esutils": "^2.0.2",
+            "lodash": "^4.17.13",
+            "to-fast-properties": "^2.0.0"
+          }
+        }
       }
     },
     "@babel/generator": {
@@ -78,9 +177,9 @@
       }
     },
     "@babel/helper-plugin-utils": {
-      "version": "7.0.0",
-      "resolved": "https://registry.npmjs.org/@babel/helper-plugin-utils/-/helper-plugin-utils-7.0.0.tgz",
-      "integrity": "sha512-CYAOUCARwExnEixLdB6sDm2dIJ/YgEAKDM1MOeMeZu9Ld/bDgVo8aiWrXwcY7OBh+1Ea2uUcVRcxKk0GJvW7QA=="
+      "version": "7.8.3",
+      "resolved": "https://registry.npmjs.org/@babel/helper-plugin-utils/-/helper-plugin-utils-7.8.3.tgz",
+      "integrity": "sha512-j+fq49Xds2smCUNYmEHF9kGNkhbet6yVIBp4e6oeQpH1RUs/Ir06xUKzDjDkGcaaokPiTNs2JBWHjaE4csUkZQ=="
     },
     "@babel/helper-split-export-declaration": {
       "version": "7.7.0",
@@ -91,13 +190,111 @@
       }
     },
     "@babel/helpers": {
-      "version": "7.7.0",
-      "resolved": "https://registry.npmjs.org/@babel/helpers/-/helpers-7.7.0.tgz",
-      "integrity": "sha512-VnNwL4YOhbejHb7x/b5F39Zdg5vIQpUUNzJwx0ww1EcVRt41bbGRZWhAURrfY32T5zTT3qwNOQFWpn+P0i0a2g==",
+      "version": "7.8.4",
+      "resolved": "https://registry.npmjs.org/@babel/helpers/-/helpers-7.8.4.tgz",
+      "integrity": "sha512-VPbe7wcQ4chu4TDQjimHv/5tj73qz88o12EPkO2ValS2QiQS/1F2SsjyIGNnAD0vF/nZS6Cf9i+vW6HIlnaR8w==",
       "requires": {
-        "@babel/template": "^7.7.0",
-        "@babel/traverse": "^7.7.0",
-        "@babel/types": "^7.7.0"
+        "@babel/template": "^7.8.3",
+        "@babel/traverse": "^7.8.4",
+        "@babel/types": "^7.8.3"
+      },
+      "dependencies": {
+        "@babel/code-frame": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.8.3.tgz",
+          "integrity": "sha512-a9gxpmdXtZEInkCSHUJDLHZVBgb1QS0jhss4cPP93EW7s+uC5bikET2twEF3KV+7rDblJcmNvTR7VJejqd2C2g==",
+          "requires": {
+            "@babel/highlight": "^7.8.3"
+          }
+        },
+        "@babel/generator": {
+          "version": "7.8.4",
+          "resolved": "https://registry.npmjs.org/@babel/generator/-/generator-7.8.4.tgz",
+          "integrity": "sha512-PwhclGdRpNAf3IxZb0YVuITPZmmrXz9zf6fH8lT4XbrmfQKr6ryBzhv593P5C6poJRciFCL/eHGW2NuGrgEyxA==",
+          "requires": {
+            "@babel/types": "^7.8.3",
+            "jsesc": "^2.5.1",
+            "lodash": "^4.17.13",
+            "source-map": "^0.5.0"
+          }
+        },
+        "@babel/helper-function-name": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/helper-function-name/-/helper-function-name-7.8.3.tgz",
+          "integrity": "sha512-BCxgX1BC2hD/oBlIFUgOCQDOPV8nSINxCwM3o93xP4P9Fq6aV5sgv2cOOITDMtCfQ+3PvHp3l689XZvAM9QyOA==",
+          "requires": {
+            "@babel/helper-get-function-arity": "^7.8.3",
+            "@babel/template": "^7.8.3",
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/helper-get-function-arity": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/helper-get-function-arity/-/helper-get-function-arity-7.8.3.tgz",
+          "integrity": "sha512-FVDR+Gd9iLjUMY1fzE2SR0IuaJToR4RkCDARVfsBBPSP53GEqSFjD8gNyxg246VUyc/ALRxFaAK8rVG7UT7xRA==",
+          "requires": {
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/helper-split-export-declaration": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.8.3.tgz",
+          "integrity": "sha512-3x3yOeyBhW851hroze7ElzdkeRXQYQbFIb7gLK1WQYsw2GWDay5gAJNw1sWJ0VFP6z5J1whqeXH/WCdCjZv6dA==",
+          "requires": {
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/highlight": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/highlight/-/highlight-7.8.3.tgz",
+          "integrity": "sha512-PX4y5xQUvy0fnEVHrYOarRPXVWafSjTW9T0Hab8gVIawpl2Sj0ORyrygANq+KjcNlSSTw0YCLSNA8OyZ1I4yEg==",
+          "requires": {
+            "chalk": "^2.0.0",
+            "esutils": "^2.0.2",
+            "js-tokens": "^4.0.0"
+          }
+        },
+        "@babel/parser": {
+          "version": "7.8.4",
+          "resolved": "https://registry.npmjs.org/@babel/parser/-/parser-7.8.4.tgz",
+          "integrity": "sha512-0fKu/QqildpXmPVaRBoXOlyBb3MC+J0A66x97qEfLOMkn3u6nfY5esWogQwi/K0BjASYy4DbnsEWnpNL6qT5Mw=="
+        },
+        "@babel/template": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/template/-/template-7.8.3.tgz",
+          "integrity": "sha512-04m87AcQgAFdvuoyiQ2kgELr2tV8B4fP/xJAVUL3Yb3bkNdMedD3d0rlSQr3PegP0cms3eHjl1F7PWlvWbU8FQ==",
+          "requires": {
+            "@babel/code-frame": "^7.8.3",
+            "@babel/parser": "^7.8.3",
+            "@babel/types": "^7.8.3"
+          }
+        },
+        "@babel/traverse": {
+          "version": "7.8.4",
+          "resolved": "https://registry.npmjs.org/@babel/traverse/-/traverse-7.8.4.tgz",
+          "integrity": "sha512-NGLJPZwnVEyBPLI+bl9y9aSnxMhsKz42so7ApAv9D+b4vAFPpY013FTS9LdKxcABoIYFU52HcYga1pPlx454mg==",
+          "requires": {
+            "@babel/code-frame": "^7.8.3",
+            "@babel/generator": "^7.8.4",
+            "@babel/helper-function-name": "^7.8.3",
+            "@babel/helper-split-export-declaration": "^7.8.3",
+            "@babel/parser": "^7.8.4",
+            "@babel/types": "^7.8.3",
+            "debug": "^4.1.0",
+            "globals": "^11.1.0",
+            "lodash": "^4.17.13"
+          }
+        },
+        "@babel/types": {
+          "version": "7.8.3",
+          "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.8.3.tgz",
+          "integrity": "sha512-jBD+G8+LWpMBBWvVcdr4QysjUE4mU/syrhN17o1u3gx0/WzJB1kwiVZAXRtWbsIPOwW8pF/YJV5+nmetPzepXg==",
+          "requires": {
+            "esutils": "^2.0.2",
+            "lodash": "^4.17.13",
+            "to-fast-properties": "^2.0.0"
+          }
+        }
       }
     },
     "@babel/highlight": {
@@ -116,26 +313,26 @@
       "integrity": "sha512-bqv+iCo9i+uLVbI0ILzKkvMorqxouI+GbV13ivcARXn9NNEabi2IEz912IgNpT/60BNXac5dgcfjb94NjsF33A=="
     },
     "@babel/plugin-proposal-do-expressions": {
-      "version": "7.6.0",
-      "resolved": "https://registry.npmjs.org/@babel/plugin-proposal-do-expressions/-/plugin-proposal-do-expressions-7.6.0.tgz",
-      "integrity": "sha512-qJDaoBDbLySwU1tG0jbAomOwz8W1PEiiiK0iLQAnHLr4PYIMVX4ltDGkj3uAKx4HDs1WJ0tozGW1zAQjuTIiWg==",
+      "version": "7.8.3",
+      "resolved": "https://registry.npmjs.org/@babel/plugin-proposal-do-expressions/-/plugin-proposal-do-expressions-7.8.3.tgz",
+      "integrity": "sha512-NoMcN+0+SS1DVswjDCfz+Jfm9ViOYuFtv1lm0QInEugbEXK2iH3jeSq38WmIiTP+2QKqo2zt8xku77gqHINZkw==",
       "requires": {
-        "@babel/helper-plugin-utils": "^7.0.0",
-        "@babel/plugin-syntax-do-expressions": "^7.2.0"
+        "@babel/helper-plugin-utils": "^7.8.3",
+        "@babel/plugin-syntax-do-expressions": "^7.8.3"
       }
     },
     "@babel/plugin-syntax-do-expressions": {
-      "version": "7.2.0",
-      "resolved": "https://registry.npmjs.org/@babel/plugin-syntax-do-expressions/-/plugin-syntax-do-expressions-7.2.0.tgz",
-      "integrity": "sha512-/u4rJ+XEmZkIhspVuKRS+7WLvm7Dky9j9TvGK5IgId8B3FKir9MG+nQxDZ9xLn10QMBvW58dZ6ABe2juSmARjg==",
+      "version": "7.8.3",
+      "resolved": "https://registry.npmjs.org/@babel/plugin-syntax-do-expressions/-/plugin-syntax-do-expressions-7.8.3.tgz",
+      "integrity": "sha512-puRiUTVDQ69iRX41eeVWqOftZK31waWqZfwKB/TGzPfgi7097twx/DpwfOfyqEGqYtvpQF3jpHwT6UBzvSyAjw==",
       "requires": {
-        "@babel/helper-plugin-utils": "^7.0.0"
+        "@babel/helper-plugin-utils": "^7.8.3"
       }
     },
     "@babel/runtime": {
-      "version": "7.7.7",
-      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.7.7.tgz",
-      "integrity": "sha512-uCnC2JEVAu8AKB5do1WRIsvrdJ0flYx/A/9f/6chdacnEZ7LmavjdsDXr5ksYBegxtuTPR5Va9/+13QF/kFkCA==",
+      "version": "7.8.4",
+      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.8.4.tgz",
+      "integrity": "sha512-neAp3zt80trRVBI1x0azq6c57aNBqYZH8KhMm3TaB7wEI5Q4A2SHfBHE8w9gOhI/lrqxtEbXZgQIrHP+wvSGwQ==",
       "requires": {
         "regenerator-runtime": "^0.13.2"
       },
@@ -656,6 +853,11 @@
       "resolved": "https://registry.npmjs.org/generic-pool/-/generic-pool-2.5.4.tgz",
       "integrity": "sha1-OMYYhRPhQDCUjsblz2VSPZd5KZs="
     },
+    "gensync": {
+      "version": "1.0.0-beta.1",
+      "resolved": "https://registry.npmjs.org/gensync/-/gensync-1.0.0-beta.1.tgz",
+      "integrity": "sha512-r8EC6NO1sngH/zdD9fiRDLdcgnbayXah+mLgManTaIZJqEC1MZstmnox8KpnI2/fxQwrp5OpCOYWLp4rBl4Jcg=="
+    },
     "github": {
       "version": "0.2.4",
       "resolved": "https://registry.npmjs.org/github/-/github-0.2.4.tgz",
@@ -1927,9 +2129,9 @@
       "integrity": "sha1-3mMSg3P8v3w8z6TeWkgMRaZ5WOs="
     },
     "resolve": {
-      "version": "1.12.0",
-      "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.12.0.tgz",
-      "integrity": "sha512-B/dOmuoAik5bKcD6s6nXDCjzUKnaDvdkRyAk6rsmsKLipWj4797iothd7jmmUhWTfinVMU+wc56rYKsit2Qy4w==",
+      "version": "1.15.1",
+      "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.15.1.tgz",
+      "integrity": "sha512-84oo6ZTtoTUpjgNEr5SJyzQhzL72gaRodsSfyxC/AXRvwu0Yse9H8eF9IpGo7b8YetZhlI6v7ZQ6bKBFV/6S7w==",
       "requires": {
         "path-parse": "^1.0.6"
       }
diff --git a/tools/tests/apps/modules/package.json b/tools/tests/apps/modules/package.json
index 2c633120b2..c7e2597040 100644
--- a/tools/tests/apps/modules/package.json
+++ b/tools/tests/apps/modules/package.json
@@ -4,9 +4,9 @@
   "description": "Test app exercising many aspects of the Meteor module system.",
   "private": true,
   "dependencies": {
-    "@babel/core": "^7.7.2",
-    "@babel/plugin-proposal-do-expressions": "^7.6.0",
-    "@babel/runtime": "^7.7.7",
+    "@babel/core": "^7.8.4",
+    "@babel/plugin-proposal-do-expressions": "^7.8.3",
+    "@babel/runtime": "^7.8.4",
     "@polymer/lit-element": "0.7.1",
     "@wry/context": "^0.4.0",
     "acorn": "file:imports/links/acorn",
diff --git a/tools/tests/apps/modules/tests.js b/tools/tests/apps/modules/tests.js
index 70ea53de36..fdd280369b 100644
--- a/tools/tests/apps/modules/tests.js
+++ b/tools/tests/apps/modules/tests.js
@@ -402,15 +402,19 @@ describe("local node_modules", () => {
   });
 
   it("can import @babel/runtime/helpers/esm/*", () => {
-    function check(exports) {
-      assert.strictEqual(typeof exports.default, "function");
-    }
-    check(require("@babel/runtime/helpers/esm/asyncIterator.js"));
-    check(require("@babel/runtime/helpers/esm/createClass.js"));
-    check(require("@babel/runtime/helpers/esm/getPrototypeOf.js"));
-    check(require("@babel/runtime/helpers/esm/inherits.js"));
-    check(require("@babel/runtime/helpers/esm/toArray.js"));
-    check(require("@babel/runtime/helpers/esm/typeof.js"));
+    import asyncIterator from "@babel/runtime/helpers/esm/asyncIterator.js";
+    import createClass from "@babel/runtime/helpers/esm/createClass.js";
+    import getPrototypeOf from "@babel/runtime/helpers/esm/getPrototypeOf.js";
+    import inherits from "@babel/runtime/helpers/esm/inherits.js";
+    import toArray from "@babel/runtime/helpers/esm/toArray.js";
+    import _typeof from "@babel/runtime/helpers/esm/typeof.js";
+
+    assert.strictEqual(typeof asyncIterator, "function");
+    assert.strictEqual(typeof createClass, "function");
+    assert.strictEqual(typeof getPrototypeOf, "function");
+    assert.strictEqual(typeof inherits, "function");
+    assert.strictEqual(typeof toArray, "function");
+    assert.strictEqual(typeof _typeof, "function");
   });
 
   it('can import packages with broken "module" fields', () => {
diff --git a/tools/utils/archinfo.ts b/tools/utils/archinfo.ts
index e3503d17b5..4d77c2d853 100644
--- a/tools/utils/archinfo.ts
+++ b/tools/utils/archinfo.ts
@@ -64,7 +64,6 @@ const utils = require('./utils');
  *   hardware is virtually extinct. Meteor has never supported it and
  *   nobody has asked for it.
  *
- * os.windows.x86_32
  * os.windows.x86_64
  *   Once, on the far side of yesterday, there was not a 64-bit
  *   build of Meteor for Windows, due to the belief that Node didn't
@@ -76,6 +75,7 @@ const utils = require('./utils');
  *   platforms show clear performance benefits over their 32-bit
  *   siblings (e.g. 7-zip, et.al), so Meteor should also try to offer
  *   that same benefit by building and offering a 64-bit version.
+ *   Meteor no longer supports Windows 32-bit.
  *
  * To be (more but far from completely) precise, the ABI for os.*
  * architectures includes a CPU type, a mode in which the code will be
@@ -131,7 +131,6 @@ export const VALID_ARCHITECTURES: Record<string, boolean> = {
   "os.osx.x86_64": true,
   "os.linux.x86_64": true,
   "os.windows.x86_64": true,
-  "os.windows.x86_32": true,
 };
 
 // Returns the fully qualified arch of this host -- something like
@@ -170,12 +169,8 @@ export function host() {
       } else {
         throw new Error(`Unsupported architecture: ${machine}`);
       }
-    } else if (platform === "win32") {
-      if (process.arch === "x64") {
-        _host = "os.windows.x86_64";
-      } else {
-        _host = "os.windows.x86_32";
-      }
+    } else if (platform === "win32" && process.arch === "x64") {
+      _host = "os.windows.x86_64";
     } else {
       throw new Error(`Unsupported operating system: ${platform}`);
     }