1536618 - Unexpected "query object's 'source' property is not undefined nor a Debugger.Source object" error during debugger request

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P1)

Description

[Logan Smyth [:loganfsmyth]]

console.error: "Error while calling actor 'source's method 'getBreakpointPositionsCompressed'" "query object's 'source' property is not undefined nor a Debugger.Source object"
console.error: "_findDebuggeeScripts@resource://devtools/server/actors/source.js:170:21\ngetBreakpointPositions@resource://devtools/server/actors/source.js:309:22\ngetBreakpointPositionsCompressed@resource://devtools/server/actors/source.js:341:24\nhandler@resource://devtools/shared/protocol.js:1189:37\nonPacket@resource://devtools/server/main.js:1291:58\nreceiveMessage@resource://devtools/shared/transport/child-transport.js:66:16\nMessageListener.receiveMessage*_addListener@resource://devtools/shared/transport/child-transport.js:40:14\nready@resource://devtools/shared/transport/child-transport.js:57:10\n_onConnection@resource://devtools/server/main.js:880:15\nconnectToParent@resource://devtools/server/main.js:296:17\nonConnect<@resource://devtools/server/startup/frame.js:59:35\nexports.makeInfallible/<@resource://devtools/shared/ThreadSafeDevToolsUtils.js:109:22\nMessageListener.receiveMessage*@resource://devtools/server/startup/frame.js:80:5\n@resource://devtools/server/startup/frame.js:160:5\n"

This is an error we'd never expect to happen. Currently triggers in one specific case I found, so I'll dig a bit more.

Comment 1

[Logan Smyth [:loganfsmyth]]

This was originally found by Jason in the test logs for the error

A promise chain failed to handle a rejection: Debugger.Source belongs to a different Debugger - stack: setBreakpointPositions/<@resource://devtools/client/debugger/new/src/actions/breakpoints/breakpointPositions.js:119:3
async*thunk/</</<@resource://devtools/client/debugger/new/src/actions/utils/middleware/thunk.js:21:45
dispatch@resource://devtools/client/shared/vendor/redux.js:755:18
loadSourceTextPromise@resource://devtools/client/debugger/new/src/actions/sources/loadSourceText.js:91:5
async*loadSourceText/</promise<@resource://devtools/client/debugger/new/src/actions/sources/loadSourceText.js:117:24
loadSourceText/<@resource://devtools/client/debugger/new/src/actions/sources/loadSourceText.js:124:9
thunk/</</<@resource://devtools/client/debugger/new/src/actions/utils/middleware/thunk.js:21:45
dispatch@resource://devtools/client/shared/vendor/redux.js:755:18
selectLocation/<@resource://devtools/client/debugger/new/src/actions/sources/select.js:138:11
thunk/</</<@resource://devtools/client/debugger/new/src/actions/utils/middleware/thunk.js:21:45
dispatch@resource://devtools/client/shared/vendor/redux.js:755:18
selectSource/<@resource://devtools/client/debugger/new/src/actions/sources/select.js:94:12
thunk/</</<@resource://devtools/client/debugger/new/src/actions/utils/middleware/thunk.js:21:45
bindActionCreator/<@resource://devtools/client/shared/vendor/redux.js:644:12
selectSource@resource://devtools/client/debugger/new/panel.js:141:26
exports.viewSourceInDebugger@resource://devtools/client/shared/view-source.js:60:17
async*viewSourceInDebugger@resource://devtools/client/framework/toolbox.js:3193:23
_debugClicked@resource://devtools/client/shared/widgets/tooltip/EventTooltipHelper.js:276:15
_headerClicked@resource://devtools/client/shared/widgets/tooltip/EventTooltipHelper.js:211:12
synthesizeMouseAtPoint@chrome://mochikit/content/tests/SimpleTest/EventUtils.js:471:13
synthesizeMouse@chrome://mochikit/content/tests/SimpleTest/EventUtils.js:405:10
@chrome://mochitests/content/browser/devtools/client/inspector/markup/test/browser_markup_view-source.js:47:14
Async*Tester_execTest/<@chrome://mochikit/content/browser-test.js:1106:34
Tester_execTest@chrome://mochikit/content/browser-test.js:1134:12
nextTest/<@chrome://mochikit/content/browser-test.js:995:14
SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:803:59

Comment 2

[Logan Smyth [:loganfsmyth]]

Both of these failures are the same more source, though I don't totally understand what is introducing the difference.

Debugger.Source belongs to a different Debugger

is the core error.

query object's 'source' property is not undefined nor a Debugger.Source object

Is actually happening because source is a Proxy wrapping the Debugger.Source object. I have no idea where the proxy is coming from, but either way they are both caused because we are initializing a source actor with a value that isn't right.

The issue is that https://bugzilla.mozilla.org/show_bug.cgi?id=1531826 introduced a call

const actor = this.targetActor.sources.getOrCreateSourceActor(script.source);

but script.source in this context is a Debugger.Source owned by the local dbg object created by devtools/server/actors/inspector/event-collector.js rather than the Debugger instance created by the thread actor itself, thus resulting in Debugger.Source belongs to a different Debugger.

We realistically shouldn't be reaching across that boundary by mixing Debugger.Source objects from multiple debugger instances.

Brian, could you look into alternative approaches to https://bugzilla.mozilla.org/show_bug.cgi?id=1531826 that might avoid this? Maybe we need a utility somewhere to adopt a Debugger.Source into a new Debugger that is debugging the same source, the same way it currently exposes adoptDebuggeeValue?

Comment 3

[Brian Hackett [Laid off!]]

Attachment: Bug 1536618 Part 1 - Add Debugger.adoptSource(), r=jorendorff.

Comment 4

[Brian Hackett [Laid off!]]

Attachment: Bug 1536618 Part 2 - Tolerate sources from any debugger in getOrCreateSourceActor, r=loganfsmyth.

Depends on D24296

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/4aad26439dcc
Part 1 - Add Debugger.adoptSource(), r=jorendorff.
https://hg.mozilla.org/integration/mozilla-inbound/rev/2ca4f2aa7160
Part 2 - Tolerate sources from any debugger in getOrCreateSourceActor, r=loganfsmyth.

Comment 6

[Brian Hackett [Laid off!]]

I had to add some extra logic to these parts to avoid wrapping sources which are in the same compartment as the debugger itself.

Comment 7

[Logan Smyth [:loganfsmyth]]

What's the motivation for not throwing for same-compartment sources?

Comment 8

[Brian Hackett [Laid off!]]

(In reply to Logan Smyth [:loganfsmyth] from comment #7)

What's the motivation for not throwing for same-compartment sources?

If we see a same-compartment source and can't provide a source actor to the inspector client, it can still use the script URL to view the source in the debugger.

Comment 9

[Logan Smyth [:loganfsmyth]]

Ah gotcha. Fair enough. Maybe in the future we can add a separate function. What threw me off is the potential for a function called getOrCreate to potentially do neither.

Comment 10

[Brian Hackett [Laid off!]]

That would be fine, though ultimately I'd like a better understanding of why the debugger is so sensitive to compartment boundaries. It would be nice if this code wasn't necessary at all.

Comment 11

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/4aad26439dcc
https://hg.mozilla.org/mozilla-central/rev/2ca4f2aa7160

Comment 12

[Peter Van der Beken [:peterv]]

https://hg.mozilla.org/projects/ash/rev/4aad26439dccf5acb5acc47df1c9146b1c1b2386
Bug 1536618 Part 1 - Add Debugger.adoptSource(), r=jorendorff.

https://hg.mozilla.org/projects/ash/rev/2ca4f2aa716088f906b640964072888891f6e5d3
Bug 1536618 Part 2 - Tolerate sources from any debugger in getOrCreateSourceActor, r=loganfsmyth.