This fails silently (modulo the well-concealed console error) and bails too early, before it finishes populating the packaged app record. So the app never appears in the Dashboard, and the user isn't told why. Also, the Dashboard stops displaying the full list of apps because of errors:

```
[12:04:54.915] Addon-message: listApps
[12:04:54.915] rendering /Users/myk/Mozilla/app-error/manifest.webapp
[12:04:54.931] rendering /Users/myk/Mozilla/app-warning/manifest.webapp
[12:04:54.932] rendering /Users/myk/Mozilla/r2d2b2g/gaia/test_apps/geoloc/manifest.webapp
[12:04:54.933] rendering /Users/myk/Mozilla/r2d2b2g/gaia/test_apps/image-uploader/manifest.webapp
[12:04:54.934] rendering /Users/myk/Mozilla/r2d2b2g/gaia/test_apps/membuster/manifest.webapp
[12:04:54.935] rendering /Users/myk/Mozilla/r2d2b2g/gaia/test_apps/template/manifest.webapp
[12:04:54.936] rendering /Users/myk/Mozilla/simulatorTestReceipt/manifest.webapp
[12:04:54.937] Addon-message: listTabs
[12:04:54.937] Addon-message: setPreference
[12:04:54.926] ReferenceError: reference to undefined property this.str[(this.index - 1)] @ resource://r2d2b2g-at-mozilla-dot-org/r2d2b2g/data/content/js/vendor/nunjucks-dev.js:1117
[12:04:54.929] TypeError: function root does not always return a value @ resource://r2d2b2g-at-mozilla-dot-org/r2d2b2g/data/content/js/vendor/nunjucks-dev.js:4008
--
[12:05:18.375] ReferenceError: reference to undefined property cur.disabled @ resource://r2d2b2g-at-mozilla-dot-org/r2d2b2g/data/content/js/vendor/jquery-1.9.1.js:3109
```

The "add app" code has accumulated some technical debt that makes fixing this complicated. Ideally we would still add the app, but we'd tell the user about the problem and provide UI for re-requesting the receipt. In the short term, however, it's ok to fail to add the app as long as we do so noticeably and don't break the dashboard in the process.

So let's do this if we fail to get the receipt: first, remove the app record from the *apps* structure; second, use simulator.error() to report the problem and prompt the user to try again, something like "Error retrieving receipt. Please try adding the app again."