1158764 - [regression] browser toolbox inspector icon missing (and other toolbar buttons)

Status: RESOLVED DUPLICATE of bug 1157906

(DevTools :: General, defect)

Description

[Patrick Brosset <:pbro>]

Attachment: missing-buttons.png

This started to happen end of last week with my fx-team build. Updated this morning, still happens.

STR:
- open the browser toolbox

Expected: The inspector pick icon appears, left of the tabs, and the other toolbar buttons are visible too, on the right side, next to the settings and close icon.

Actual: None of these icons appear.

There's an exception in the logs when that happens:

onPacket threw an exception: Error: Server did not specify an actor, dropping packet: [{"item":"command","name":"pref","params":[],"isParent":true,"description":"Commands to control settings","manual":"Commands to display and alter preferences both for GCLI and the surrounding environment"}, ... very long serialized js object ...
Stack: DebuggerClient.prototype.onPacket@resource://gre/modules/devtools/dbg-client.jsm:944:1
DebuggerTransport.prototype._onJSONObjectReady/<@resource://gre/modules/devtools/dbg-client.jsm -> resource://gre/modules/devtools/transport/transport.js:471:9
makeInfallible/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/DevToolsUtils.js:82:14
makeInfallible/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/DevToolsUtils.js:82:14
Line: 944, column: 0

Comment 1

[Patrick Brosset <:pbro>]

Attachment: settings-panel.png

Switching to the settings panel, I can confirm that both the "pick an element from the page" and "select an iframe as the currently targeted document" checkboxes are checked.
Still none of these buttons are shown.

Interestingly, if I uncheck the "pick an element from the page" checkbox, then the iframe selector appears. And if I check again the "pick an element from the page" checkbox, then the inspector icon appears too.