I am seeing an exception in the Browser console (Fission disabled)

TypeError: this._debuggerSourcesSeen is null: _addSource@resource://devtools/server/actors/thread.js:1998:7
addAllSources@resource://devtools/server/actors/thread.js:1324:12
_onWindowReady@resource://devtools/server/actors/thread.js:1727:12

See Details:
https://gist.github.com/janodvarko/ad6c2f11df3e186689913394d90840ea

STR:

0. Set devtools.netmonitor.features.search pref to true
1. Open the Content Toolbox and select the Network panel
2. Load http://janodvarko.cz/xhr-spy/
3. Resume the break on debugger statement
4. Go the to Network panel again
5. Click the Search button in the Toolbar and search for mouse
6. Expand the first search result group and select the first search match (setcookie) - the right Response side panel should open and select the setcookie line
7. Close the Search panel
8. Select the Headers panel and back the Response panel

Watch the Browser Console for an exception

Honza

Jason, can you please look at this, thanks!
Honza

I was not able to reproduce. Looking at the code, I see two possible explanations:

1. the thread was not attached, that seems unlikely because we addSource is primarily called by onNewScript.
2. the thread was detatched, which seems unlikely given that devtools is open and you have used the debugger to resume...

Could you try and reproduce this again? If it reproduces consistently, could you add console.log(new Error('hi').stack) at the top of _addSource so we see who is calling addSource?

I can still reproduce that.

Here is the requested stack-trace:

_addSource@resource://devtools/server/actors/thread.js:1990:17
addAllSources@resource://devtools/server/actors/thread.js:1326:12
_onWindowReady@resource://devtools/server/actors/thread.js:1729:12
emit@resource://devtools/shared/event-emitter.js:190:24
emit@resource://devtools/shared/event-emitter.js:271:18
_windowReady@resource://devtools/server/actors/targets/browsing-context.js:1373:10
DebuggerProgressListener.prototype.onWindowCreated<@resource://devtools/server/actors/targets/browsing-context.js:1671:23
exports.makeInfallible/<@resource://devtools/shared/ThreadSafeDevToolsUtils.js:111:22
EventListener.handleEvent*watch@resource://devtools/server/actors/targets/browsing-context.js:1592:13
_watchDocshells@resource://devtools/server/actors/targets/browsing-context.js:635:28
_attach/<@resource://devtools/server/actors/targets/browsing-context.js:622:42
DevToolsUtils.executeSoon*exports.executeSoon@resource://devtools/shared/DevToolsUtils.js:62:21
_attach@resource://devtools/server/actors/targets/browsing-context.js:622:19
parentProcessTargetPrototype._attach@resource://devtools/server/actors/targets/parent-process.js:144:48
attach@resource://devtools/server/actors/targets/browsing-context.js:1035:10
handler@resource://devtools/shared/protocol/Actor.js:154:37
onPacket@resource://devtools/server/debugger-server-connection.js:378:58
send/<@resource://devtools/shared/transport/local-transport.js:70:25
exports.makeInfallible/<@resource://devtools/shared/ThreadSafeDevToolsUtils.js:111:22
DevToolsUtils.executeSoon*exports.executeSoon@resource://devtools/shared/DevToolsUtils.js:62:21
send@resource://devtools/shared/transport/local-transport.js:58:21
send@resource://devtools/shared/protocol/Front.js:160:30
request@resource://devtools/shared/protocol/Front.js:178:10
generateRequestMethods/</frontProto[name]@resource://devtools/shared/protocol/Front/FrontClassWithSpec.js:49:19
attach/this._attach<@resource://devtools/shared/fronts/targets/browsing-context.js:104:36
attach@resource://devtools/shared/fronts/targets/browsing-context.js:116:7
getTarget/this._targetFrontPromise<@resource://devtools/shared/fronts/descriptors/process.js:70:40
async*getTarget@resource://devtools/shared/fronts/descriptors/process.js:83:7
getProcess@resource://devtools/shared/fronts/root.js:228:37
async*getMainProcess@resource://devtools/shared/fronts/root.js:219:17
connect@resource://devtools/client/webconsole/browser-console-manager.js:139:42
async*toggleBrowserConsole/this._browserConsoleInitializing<@resource://devtools/client/webconsole/browser-console-manager.js:101:33
toggleBrowserConsole@resource://devtools/client/webconsole/browser-console-manager.js:106:7
openBrowserConsoleOrFocus@resource://devtools/client/webconsole/browser-console-manager.js:182:17
onKeyShortcut@resource://devtools/client/framework/devtools-browser.js:373:31
onKey@resource:///modules/DevToolsStartup.jsm:766:32
attachKeys/xulKey<@resource:///modules/DevToolsStartup.jsm:690:58
EventListener.handleEvent*createKey@resource:///modules/DevToolsStartup.jsm:800:7
attachKeys@resource:///modules/DevToolsStartup.jsm:690:27
hookKeyShortcuts@resource:///modules/DevToolsStartup.jsm:668:10
hookWindow@resource:///modules/DevToolsStartup.jsm:458:10
onWindowReady@resource:///modules/DevToolsStartup.jsm:414:10
_delayedStartup@chrome://browser/content/browser.js:2152:18
EventListener.handleEvent*onLoad@chrome://browser/content/browser.js:1896:12
EventHandlerNonNull*@chrome://browser/content/browser.xhtml:118:39

I am not able to reproduce the problem on MacOS
On Mac I only see this exception:

Security Error: Content at moz-nullprincipal:{a76130cb-982c-40f4-84c4-2187d40ceac7} may not load or link to chrome://devtools/content/netmonitor/non-existing-image.

Honza