Privacy/Docs/How To Triage ETP-Strict Website Breakage

Steps on how to triage Web Compatibility :: Privacy: Site Reports bugs.

Triage tools:

• BugDash

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.skipURLs
• urlclassifier.features.emailtracking.datacollection.skipURLs
• urlclassifier.features.emailtracking.skipURLs
• urlclassifier.features.fingerprinting.skipURLs
• urlclassifier.features.socialtracking.skipURLs
• urlclassifier.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 diagnose 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)

Service Workers in Private Browsing Mode

Until Bug 1320796 - Support ServiceWorkers in Private Browsing Mode resolves, checking for private browsing-only bugs whether a service worker registers in normal browsing mode is indicative of breakage being due to non-existing service-worker support. Whether a service worker registers can be checked in about:serviceworkers. If service worker is the cause, the breakage bug should depend on Bug 1320796.

Service worker in Private browsing is targetted for the 140 release Bug 1959535, Bug 1967568.

Test different cookie modes

• Check whether the bug is caused by TCP (Total Cookie Protection): By setting network.cookie.cookieBehavior to 4
• Check whether it is caused by the soon-to-be-deprecated tracker-cookie-blocking: network.cookie.cookieBehavior.trackerCookieBlocking to false. network.cookie.cookieBehavior has to be 5

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).

List with rough size of meta available under Privacy/Triage/Tp-Breakage

Full Query

ID	Summary	Alias	Cc count
1101005	[meta] ETP Strict mode or Private Browsing mode tracking protection breakage	tp-breakage	30
1400025	[meta] Tracking Protection breaks embedded videos	tp-breakage-video	9
1470298	[meta] Tracking Protection breaks login	tplogin	11
1470301	[meta] Tracking Protection breaks images	tpimages	6
1527013	[meta] Fingerprinting blocking breakage bugs	fp-blocking-breakage	10
1627322	[meta] Tracking Protection breaks sites relying on Facebook resources	tp-facebook	6
1628148	[meta] Tracking Protection breaks storefronts using Digital River	tp-digital-river	2
1628154	[meta] Tracking Protection breakage related to Google ad services	tp-googleads	2
1628157	[meta] Tracking Protection breakage related to blocked Reddit resources	tp-reddit	2
1628161	[meta] Tracking Protection breaks sites relying on Mailchimp resources	tp-mailchimp	4
1628170	[meta] Tracking Protection breakage related to Google Analytics	tp-googleanalytics	3
1628176	[meta] Tracking Protection breaks sites relying on Twitter resources	tp-twitter	6
1631091	[meta] Tracking Protection breaks sites relying on Instagram resources	tp-instagram	4
1707917	[meta] Issues with Amazon web services in Strict ETP/Private Browsing	tp-amazon	2
1707939	[meta] Resources hosted on userapi.com are blocked by ETP strict/private browsing.	tp-userapi	3
1773110	[meta] Private browsing mode breakage which seems to be due to missing web APIs	tp-pbm-missing-api-breakage	7
1773111	[meta] Breakage which seems related to iOS/ITP antitracking	tp-ios	3
1797458	[meta] Email Tracking Breakage	email-tp-breakage	5
1874647	[meta] ETP breakage for webpages part of the "Sinclair Broadcast Group"	tp-breakage-sinclair	3
1875061	[meta] ETP breakage for webpages that have Disqus comment section	tp-breakage-disqus	11
1899334	[meta] Breakage bugs for cookie management providers due to tracking protection	tp-breakage-cmp	4
1909492	[meta] Firefox in private mode blocks scripts from *.ondemand.com (ETP)	No alias	4
1931743	[meta] Facebook games breakage bugs	tp-breakage-fb-games	1
1934762	[meta] Captcha breakage	tp-breakage-captcha	1
1944600	[meta] Tracking Protection shims break websites	tp-breakage-shim	No cc_count
1959711	[meta] Login via Google broken in ETP-Strict for some sites or ETP Standard in private browsing	tp-breakage-login-via-google	1
1985994	[meta] SmartBlock Opt-in listings breakage	tp-smartblock-breakage	1

27 Total; 27 Open (100%); 0 Resolved (0%); 0 Verified (0%);

Docs

• Privacy Team - Bug triage
• Guidelines for Handling Privacy Site Report Bugs
• ETP/WebCompat Bug Classification Effort