Privacy/Docs/How To Triage ETP-Strict Website Breakage
Steps on how to triage Web Compatibility :: Privacy: Site Reports bugs.
Triage tools:
Triage helper Addon: Site Issue Triage (on Github)
about:config
Usually exceptions can be set via urlclassifier.trackingSkipURLs. However, sometimes the tracker is on other lists as well. Use about:url-classifier to see which exception list you need to put the tracking URL and enter the domain in one of these lists:
urlclassifier.features.cryptomining.skipURLsurlclassifier.features.emailtracking.datacollection.skipURLsurlclassifier.features.emailtracking.skipURLsurlclassifier.features.fingerprinting.skipURLsurlclassifier.features.socialtracking.skipURLsurlclassifier.trackingSkipURLs
The content of the config variable needs to be a list of domains including subdomains: Example: *://*.example.com/*,*://example.com/*,*://sub.example.net/*
Identifying blocked URLs
Go to networking tab in devtools and sort by transferred to see all blocked URLs. In theory setting MOZ_LOG=nsChannelClassifier:5 also outputs information about classified URLs.
Putting diagnosis into bug
Marking a bug as diagnosed: [privacy-team:diagnosed] in whiteboard (when identified the root cause, usually meaning list of necessary urls to unblock identified and put into the User story as trackers-blocked:xyz.com,*.abc.com). Also, you should add either [exception-baseline] or [exception-convenience] to the whiteboard, depending on if it is critical for the site to function.
Test different cookie modes
- Check whether the bug is caused by TCP (Total Cookie Protection): By setting
network.cookie.cookieBehaviorto4 - Check whether it is caused by the soon-to-be-deprecated tracker-cookie-blocking:
network.cookie.cookieBehavior.trackerCookieBlockingtofalse.network.cookie.cookieBehaviorhas to be5
Shims breaking websites
Sometimes shims can cause breakage for websites. Go to the "Console" tab of devtools to see which shims are applied to a website. A yellow message such as Google Publisher Tags is being shimmed by Firefox. See https://bugzilla.mozilla.org/show_bug.cgi?id=1713685 for details. gets displayed.
Go to `about:compat` and disable all applied shims to see whether that unbreaks the website. Look whether there is a bug blocking Bug 1944600 already open. Otherwise open one yourself with Bug 1944600 as blocking bug and set your breakage bug as depending.
Running clear profiles
Normal
./mach mozregression --launch $(date -d yesterday +%Y-%m-%d) --pref urlclassifier.trackingSkipURLs:
With ETP-Strict:
./mach mozregression --launch $(date -d yesterday +%Y-%m-%d) --pref browser.contentblocking.category:strict --pref urlclassifier.trackingSkipURLs:
Blocking the correct meta bug
Block the correct meta bug or Bug 1101005 when no meta bug for the breakage exist. There is no hard rule, but when there are 3+ bugs with the same cause it is worth considering opening a meta bug for it. All meta bugs should block bug 1960641 (tp-breakage-metas).
If the bug was caused by tracking protection, you should make sure the bug has the keyword webcompat:tracker-blocking.
List with rough size of meta available under Privacy/Triage/Tp-Breakage
Meta bugs for breakage due to tracking protection with resource blocking:
31 Total; 31 Open (100%); 0 Resolved (0%); 0 Verified (0%);
Meta bugs for breakge of other causes:
| ID | Summary | Alias | Cc count |
|---|---|---|---|
| 1480137 | [meta] breakage bug for tracking cookie restrictions | etp-breakage | 15 |
| 1602922 | [meta] Breakage bugs of Dynamic First Party Isolation | dfpi-breakage | 15 |
| 1657930 | [meta] - Strict ETP Facebook login breakage (that our shimming should in theory fix) | No alias | 5 |
| 1669486 | [Meta] Web compatibility issues caused by ETP Level 2 | etp-level-2-webcompat | 4 |
| 1834329 | [meta] Breakage from Fingerprinting Protection | No alias | 2 |
| 1917788 | [meta] Third-party cookie deprecation breakage | 3pcd-breakage | 5 |
| 1957426 | [meta] Canvas Noise Breakage | canvas-noise-breakage | 2 |
| 1972297 | [meta] Website breakage due to sending Global Privacy Control Header "Sec-GPC: 1" | tp-breakage-gpc | No cc_count |
8 Total; 8 Open (100%); 0 Resolved (0%); 0 Verified (0%);