'Unable to retrieve manifest' when manifest file is available but invalid

[samdutton]

The manifest for my site was actually invalid, but the Lighthouse report looks as if the manifest file couldn't be retrieved:

[brendankenny]

do you have a test url/can you leave it invalid so we can debug it? :)

Lighthouse uses the debugger protocol to retrieve the manifest and it's possible it's dropping an error message being passed over.

[samdutton]

Sure :).

I just broke it again for you:

https://apprtc-pwa.appspot.com

[paulirish]

I added this:

and got this:

[paulirish]

@samdutton would this work for you?

[paulirish]

PR up at #2349

[samdutton]

That was quick :). Perfect — thanks.

[paulirish]

We never surface response.errors. We should.

lighthouse/lighthouse-core/gather/driver.js

Lines 552 to 554 in d9e1a32

	// We're not reading `response.errors` however it may contain critical and noncritical
	// errors from Blink's manifest parser:
	// https://chromedevtools.github.io/debugger-protocol-viewer/tot/Page/#type-AppManifestError

These errors may be included in #8223 .. Not 100% sure.

[wardpeet]

I'm closing this one as a duplicate of #1666.