SW fails to fetch spec CSS on first load of the day

[tabatkins]

On the first load of the day (or any load after a SW refresh, I imagine), WHATWG specs fail to load their CSS in current chrome (100). The following errors show up in the console:

The FetchEvent for "https://resources.whatwg.org/spec.css" resulted in a network error response: 
an "opaque" response was used for a request whose type is not no-cors
The FetchEvent for "https://resources.whatwg.org/standard.css" resulted in a network error response: 
an "opaque" response was used for a request whose type is not no-cors
The FetchEvent for "https://resources.whatwg.org/standard-shared-with-dev.css" resulted in a network error response: 
an "opaque" response was used for a request whose type is not no-cors

After a refresh these succeed and the spec is formatted normally.

[domenic]

Seems very similar to #253, perhaps even a dupe, but it sounds like you have a deterministic repro which was not the case for me...

[tabatkins]

Hm, I got it to reproduce immediately by stopping and restarting the SW then refreshing, but now that doesn't work again.

Regardless, it's definitely happening approximately daily for me, if you want to fiddle and have a slow back-and-forth debugging.