2024409 - Crash when an observation that a pref value changed occurs

Status: RESOLVED WORKSFORME

(Firefox for Android :: Experimentation and Telemetry, task)

Description

[Olivia Hall [:olivia]]

Attachment: default-changed-error.log

I'm investigating an issue that occurs when a pref changes. There seems to be some parsing issue. This bug is more of a placeholder while I investigate more. Logs attached.

One STR, can happen in other observation scenarios, like user branch:

Basic changed prefs - Default Pref Branch

1. Install app and note preference values
2. Update user preference value
3. Activate nimbus-cli experiment
4. Check prefs in about:config by toggling back

  gecko-nimbus-validation-multi-pref-user:
    description: "Feature for validating Nimbus Gecko functionality with multiple preference types on user branch"
    variables:
      anchor-color-dark:
        description: "Shipped default #00CADB"
        type: String
        default: "#000000"
        gecko-pref:
          pref: "browser.anchor_color.dark"
          branch: "user"
      autofocus:
        description: "Shipped default false"
        type: Boolean
        default: false
        gecko-pref:
          pref: "browser.autofocus"
          branch: "default"

Happens on browser.anchor_color.dark case when toggling back to the default in about config after launching an nimbus-cli experiment set those values.

Comment 1

[Olivia Hall [:olivia]]

Note: This doesn't seem to always happen, but can happen somewhat frequently under the STR.

Comment 2

[Olivia Hall [:olivia]]

Might be fixed or related to bug 2024298. I haven't performed specific testing against this case since the fix.

Comment 3

[Olivia Hall [:olivia]]

I think this was fixed by bug 2024298 or bug 2025607 (there is a Lifting custom type serde_json::value::Value from FFI type alloc::string::String in the trace too.)

Didn't see it on my second testing round on bug 2001415 and couldn't reproduce just now.