raw.name! is undefined in debug-source.ts

[BrightKn1ght]

I have quite complex remote debug behavior of a python script using debugpy and Theia 1.55.1.

Bug Description:

When I launch the debugging an exceptions occurs at:

logger-protocol.js:97 2025-03-03T08:41:11.187Z root ERROR fetchFrames failed: TypeError: Cannot read properties of undefined (reading 'toString')
    at r.withPath (https://localhost:8443/ide/bundle.js:2:8399171)
    at a.toUri (https://localhost:8443/ide/bundle.js:2:3186482)
    at s.getSource (https://localhost:8443/ide/bundle.js:2:7810185)
    at t.DebugStackFrame.update (https://localhost:8443/ide/bundle.js:2:9996831)
    at t.DebugThread.doUpdateFrames (https://localhost:8443/ide/bundle.js:2:6856289)
    at https://localhost:8443/ide/bundle.js:2:6855626

It turns out that in debug-source.ts at line 83 the raw.name! is undefined:

static toUri(raw: DebugProtocol.Source): URI {
        if (raw.sourceReference && raw.sourceReference > 0) {
            return new URI().withScheme(DEBUG_SCHEME).withPath(raw.name!).withQuery(String(raw.sourceReference)); // <-- Usage of name without check
        }
        if (!raw.path) {
            throw new Error('Unrecognized source type: ' + JSON.stringify(raw));
        }
        if (raw.path.match(SCHEME_PATTERN)) {
            return new URI(raw.path);
        }
        return new URI(Uri.file(raw.path));
    }

Does someone know how this could happen?

Steps to Reproduce:

1. I think my setup is too complex to reproduce.

What I found out from looking at debugpy logs, is that debugpy is kind of creating translations for file paths:

0.00s - sending cmd (http_json) -->           CMD_RETURN {"type": "response", "request_seq": 14, "success": true, "command": "threads", "body": {"threads": [{"id": 1, "name": "MainThread"}]}, "seq": 36, "pydevd_cmd_id": 502}

0.00s - Process StackTraceRequest: {
    "arguments": {
        "format": {},
        "levels": 1,
        "startFrame": 0,
        "threadId": 1
    },
    "command": "stackTrace",
    "seq": 15,
    "type": "request"
}

0.00s - Created source reference: 1 for untranslated path: /var/snap/rexroth-automationcore/common/solutions/activeConfiguration/scripts/bosch/tiger/16uhr--d34d2e4d-c5d6-41b6-9f1b-82156db6b20d.py
0.00s - sending cmd (http_json) -->     CMD_MODULE_EVENT {"type": "event", "event": "module", "body": {"reason": "new", "module": {"id": 0, "name": "__main__", "path": "/var/snap/rexroth-automationcore/common/solutions/activeConfiguration/scripts/bosch/tiger/16uhr--d34d2e4d-c5d6-41b6-9f1b-82156db6b20d.py", "package": "None"}}, "seq": 38, "pydevd_cmd_id": 203}

0.00s - Created source reference: 2 for untranslated path: <string>
0.00s - sending cmd (http_json) -->     CMD_MODULE_EVENT {"type": "event", "event": "module", "body": {"reason": "new", "module": {"id": 1, "name": "__main__", "path": "<string>", "package": "None"}}, "seq": 40, "pydevd_cmd_id": 203}

0.00s - sending cmd (http_json) -->           CMD_RETURN {"type": "response", "request_seq": 15, "success": true, "command": "stackTrace", "body": {"stackFrames": [{"id": 2, "name": "<module>", "line": 27, "column": 1, "source": {"path": "/var/snap/rexroth-automationcore/common/solutions/activeConfiguration/scripts/bosch/tiger/16uhr--d34d2e4d-c5d6-41b6-9f1b-82156db6b20d.py", "sourceReference": 1}}], "totalFrames": 2}, "seq": 42, "pydevd_cmd_id": 502}

And when theia finds info about sourceReference in debug-source.ts it tries to build the URL from that:
return new URI().withScheme(DEBUG_SCHEME).withPath(raw.name!).withQuery(String(raw.sourceReference));

Additional Information

• Operating System:
• Theia Version: 1.55.1 Community Release
• Full debugpy log:
  debugpy.pydevd.12791.log