SystemJS (Aurelia with jspm) fails to load “aurelia-pal-browser” from jspm_packages folder

问题

I've followed the instructions at https://www.danylkoweb.com/Blog/getting-started-with-aurelia-in-aspnet-mvc-EH, step 3-5 to install Aurelia in to my asp.net mvc core app (i.e. running npm install, jspm init, jspm install aurelia-framework and jspm install aurelia-bootstrapper).

My "startup code" just looks like this for now:

<script src="jspm_packages/system.js"></script>
<script src="config.js"></script>
<script>
    SystemJS.import('aurelia-bootstrapper');
</script>

When I run the application I can see on Chrome dev tools that a lot of Aurelia resources (js files) are loaded under the /jspm_packages/npm folder, but I also get an error like this:

Uncaught (in promise) Error: (SystemJS) XHR error (404 Not Found) loading http://localhost:39535/aurelia-pal-browser.js Error: XHR error (404 Not Found) loading http://localhost:39535/aurelia-pal-browser.js Error loading http://localhost:39535/aurelia-pal-browser.js

For some reason SystemJS starts looking for aurelia-pal-browser.js in the root of my application. I suppose it can't find the jspm_packages\npm\aurelia-pal-browser@1.1.0 folder but it's there and I have that same version number in the config.js file.

Full config.js as I got it after running the jspm commands:

System.config({
  baseURL: "/",
  defaultJSExtensions: true,
  transpiler: false,
  paths: {
    "npm:*": "jspm_packages/npm/*"
  },

  map: {
    "aurelia-bootstrapper": "npm:aurelia-bootstrapper@2.0.1",
    "aurelia-framework": "npm:aurelia-framework@1.0.8",
    "npm:aurelia-binding@1.1.1": {
      "aurelia-logging": "npm:aurelia-logging@1.2.0",
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-pal": "npm:aurelia-pal@1.2.0",
      "aurelia-task-queue": "npm:aurelia-task-queue@1.1.0"
    },
    "npm:aurelia-bootstrapper@2.0.1": {
      "aurelia-event-aggregator": "npm:aurelia-event-aggregator@1.0.1",
      "aurelia-framework": "npm:aurelia-framework@1.0.8",
      "aurelia-history": "npm:aurelia-history@1.0.0",
      "aurelia-history-browser": "npm:aurelia-history-browser@1.0.0",
      "aurelia-loader-default": "npm:aurelia-loader-default@1.0.0",
      "aurelia-logging-console": "npm:aurelia-logging-console@1.0.0",
      "aurelia-pal": "npm:aurelia-pal@1.2.0",
      "aurelia-pal-browser": "npm:aurelia-pal-browser@1.1.0",
      "aurelia-polyfills": "npm:aurelia-polyfills@1.1.1",
      "aurelia-router": "npm:aurelia-router@1.1.1",
      "aurelia-templating": "npm:aurelia-templating@1.1.4",
      "aurelia-templating-binding": "npm:aurelia-templating-binding@1.1.0",
      "aurelia-templating-resources": "npm:aurelia-templating-resources@1.2.0",
      "aurelia-templating-router": "npm:aurelia-templating-router@1.0.1"
    },
    "npm:aurelia-dependency-injection@1.2.1": {
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-pal": "npm:aurelia-pal@1.2.0"
    },
    "npm:aurelia-event-aggregator@1.0.1": {
      "aurelia-logging": "npm:aurelia-logging@1.2.0"
    },
    "npm:aurelia-framework@1.0.8": {
      "aurelia-binding": "npm:aurelia-binding@1.1.1",
      "aurelia-dependency-injection": "npm:aurelia-dependency-injection@1.2.1",
      "aurelia-loader": "npm:aurelia-loader@1.0.0",
      "aurelia-logging": "npm:aurelia-logging@1.2.0",
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-pal": "npm:aurelia-pal@1.2.0",
      "aurelia-path": "npm:aurelia-path@1.1.1",
      "aurelia-task-queue": "npm:aurelia-task-queue@1.1.0",
      "aurelia-templating": "npm:aurelia-templating@1.1.4"
    },
    "npm:aurelia-history-browser@1.0.0": {
      "aurelia-history": "npm:aurelia-history@1.0.0",
      "aurelia-pal": "npm:aurelia-pal@1.2.0"
    },
    "npm:aurelia-loader-default@1.0.0": {
      "aurelia-loader": "npm:aurelia-loader@1.0.0",
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-pal": "npm:aurelia-pal@1.2.0"
    },
    "npm:aurelia-loader@1.0.0": {
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-path": "npm:aurelia-path@1.1.1"
    },
    "npm:aurelia-logging-console@1.0.0": {
      "aurelia-logging": "npm:aurelia-logging@1.2.0"
    },
    "npm:aurelia-metadata@1.0.3": {
      "aurelia-pal": "npm:aurelia-pal@1.2.0"
    },
    "npm:aurelia-pal-browser@1.1.0": {
      "aurelia-pal": "npm:aurelia-pal@1.2.0"
    },
    "npm:aurelia-polyfills@1.1.1": {
      "aurelia-pal": "npm:aurelia-pal@1.2.0"
    },
    "npm:aurelia-route-recognizer@1.1.0": {
      "aurelia-path": "npm:aurelia-path@1.1.1"
    },
    "npm:aurelia-router@1.1.1": {
      "aurelia-dependency-injection": "npm:aurelia-dependency-injection@1.2.1",
      "aurelia-event-aggregator": "npm:aurelia-event-aggregator@1.0.1",
      "aurelia-history": "npm:aurelia-history@1.0.0",
      "aurelia-logging": "npm:aurelia-logging@1.2.0",
      "aurelia-path": "npm:aurelia-path@1.1.1",
      "aurelia-route-recognizer": "npm:aurelia-route-recognizer@1.1.0"
    },
    "npm:aurelia-task-queue@1.1.0": {
      "aurelia-pal": "npm:aurelia-pal@1.2.0"
    },
    "npm:aurelia-templating-binding@1.1.0": {
      "aurelia-binding": "npm:aurelia-binding@1.1.1",
      "aurelia-logging": "npm:aurelia-logging@1.2.0",
      "aurelia-templating": "npm:aurelia-templating@1.1.4"
    },
    "npm:aurelia-templating-resources@1.2.0": {
      "aurelia-binding": "npm:aurelia-binding@1.1.1",
      "aurelia-dependency-injection": "npm:aurelia-dependency-injection@1.2.1",
      "aurelia-loader": "npm:aurelia-loader@1.0.0",
      "aurelia-logging": "npm:aurelia-logging@1.2.0",
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-pal": "npm:aurelia-pal@1.2.0",
      "aurelia-path": "npm:aurelia-path@1.1.1",
      "aurelia-task-queue": "npm:aurelia-task-queue@1.1.0",
      "aurelia-templating": "npm:aurelia-templating@1.1.4"
    },
    "npm:aurelia-templating-router@1.0.1": {
      "aurelia-binding": "npm:aurelia-binding@1.1.1",
      "aurelia-dependency-injection": "npm:aurelia-dependency-injection@1.2.1",
      "aurelia-logging": "npm:aurelia-logging@1.2.0",
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-pal": "npm:aurelia-pal@1.2.0",
      "aurelia-path": "npm:aurelia-path@1.1.1",
      "aurelia-router": "npm:aurelia-router@1.1.1",
      "aurelia-templating": "npm:aurelia-templating@1.1.4"
    },
    "npm:aurelia-templating@1.1.4": {
      "aurelia-binding": "npm:aurelia-binding@1.1.1",
      "aurelia-dependency-injection": "npm:aurelia-dependency-injection@1.2.1",
      "aurelia-loader": "npm:aurelia-loader@1.0.0",
      "aurelia-logging": "npm:aurelia-logging@1.2.0",
      "aurelia-metadata": "npm:aurelia-metadata@1.0.3",
      "aurelia-pal": "npm:aurelia-pal@1.2.0",
      "aurelia-path": "npm:aurelia-path@1.1.1",
      "aurelia-task-queue": "npm:aurelia-task-queue@1.1.0"
    }
  }
});

回答1:

I did not read your linked article, but what you may try is install aurelia-pal-browser@1.1.0 as a dependency as well so it is explicitly listed in your package.json and your config.js.

Simply execute the following on the cmd line:

jspm install npm:aurelia-pal-browser

来源：https://stackoverflow.com/questions/41522750/systemjs-aurelia-with-jspm-fails-to-load-aurelia-pal-browser-from-jspm-packa