There is some weird code path that causes the Inspector to initialize when you cmd+opt+i to toggle on the tools and the last panel opened was a11y. We should check if the inspector is visible before showing the 3 pane onboarding tooltip. STR 1. Open a11y panel 2. Close devtools 3. Open devtools (should default to opening the last opened panel - a11y) 4. Inspector code path is initialized 5. See 3 pane onboarding tooltip in a11y panel

Comment on attachment 8973278 [details] Bug 1459257 - Check the inspector is visible before showing the 3 pane onboarding tooltip. https://reviewboard.mozilla.org/r/241744/#review247602 Looks good to me, let's just add a comment. ::: devtools/client/inspector/inspector.js:299 (Diff revision 1) > } > > // Setup the toolbar only now because it may depend on the document. > await this.setupToolbar(); > > - if (this.show3PaneTooltip) { > + if (this.show3PaneTooltip && this.toolbox.currentToolId === "inspector") { Let's add a comment to explain why this is needed.

Pushed by gabriel.luong@gmail.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/af05b5813fc7 Check the inspector is visible before showing the 3 pane onboarding tooltip. r=jdescottes