Minification breaks regenerator-runtime package and redux-saga is not usable

[navarroaxel]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?
The regenerator-runtime@0.10.5/runtime.js is not minified properly. Throwing the following error:

ExceptionsManager.js:73 uncaught at n at n 
 ReferenceError: record is not defined
    at Generator._invoke (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:221:931)
    at Generator.t.(anonymous function) [as next] (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:221:1352)
    at t (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:869:536)
    at o (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:869:7374)
    at t.runSaga (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:867:806)
    at o.default (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:865:440)
    at http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:514:173
    at t (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:2:1273)
    at http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:2:614
    at n (http://localhost:8081/index.android.bundle?platform=android&dev=true&minify=true:2:622)

This is the original code:

var record = tryCatch(innerFn, self, context);
if (record.type === "normal") {

This is the minified:

if (o = b, "normal" === (record = n(t, r, e)).type) {

The regenerator-runtime/runtime.js has this header with strict mode enabled (this cause the error):

!(function(global) {
  "use strict";

With this error the redux-saga package is unusable and the whole app is broken.

If the current behavior is a bug, please provide the steps to reproduce and a minimal repository on GitHub that we can yarn install and yarn test.

What is the expected behavior?
The record variable is well defined. Work fine on:

react-native@0.49.3
metro-bundler@0.13.0

Please provide your exact metro-bundler configuration and mention your metro-bundler, node, yarn/npm version and operating system.

node@6.11.5
yarn@1.13.2
metro-bundler@0.20.0
react-native@0.50.1
regenerator-runtime@0.10.5
redux-saga@0.16.0
OS: Ubuntu MATE 16.04.3 LTS

[rafeca]

@navarroaxel I have just released metro-bundler@0.20.1 with an upgraded uglify version, which hopefully will fix this.

You can force yarn to use the new metro version by forcing a resolution in your package.json:

"resolutions": {
  "metro-bundler": "0.20.1"
}

Please reopen the issue if this does not fix it