1599055 - Targets.watchForTabs causes warning: Lazy browser prematurely inserted via 'messageManager'

Status: RESOLVED WONTFIX

(Remote Protocol :: CDP, defect, P3)

Description

[Andreas Tolfsen ❲:ato❳]

When starting a debug build of Firefox with the remote debugger enabled:

./mach run --setpref="remote.enabled=true" -- --headless --remote-debugger

I see this warning:

console.log: "[bug 1345098] Lazy browser prematurely inserted via 'messageManager' property access:
getter@chrome://browser/content/tabbrowser.js:2322:39
watchForTabs/<@chrome://remote/content/targets/Targets.jsm:61:9
emit@resource://gre/modules/EventEmitter.jsm:160:20
onTabOpen@chrome://remote/content/targets/TabObserver.jsm:117:10
onWindowOpen@chrome://remote/content/targets/TabObserver.jsm:138:12
emit@resource://gre/modules/EventEmitter.jsm:160:20
onOpenDOMWindow@chrome://remote/content/targets/TabObserver.jsm:58:10
async*start@chrome://remote/content/targets/TabObserver.jsm:45:20
start@chrome://remote/content/targets/TabObserver.jsm:102:24
watchForTabs@chrome://remote/content/targets/Targets.jsm:77:28
watchForTargets@chrome://remote/content/targets/Targets.jsm:37:16
listen@chrome://remote/content/RemoteAgent.jsm:81:26
_scheduleStartupIdleTasks/<@resource:///modules/BrowserGlue.jsm:2187:22
"

It is possible we are doing the correct thing because we want to track lazy (unloaded) tabs,
as they otherwise won’t be accessible when listing the available targets.

But we should probably investigate this further to make sure our behaviour is correct.

Edit: Broke the message by newline.

Comment 1

[Henrik Skupin [:whimboo][⌚️UTC+2]]

We are not going to fix that in our CDP implementation.