Implementing a DAP Client

[gunpal5]

I want to code a standalone debugger. I was testing DAP for this. I wrote DAP client APIs. but when I try to debug through my implementation debugpy just start the debugging and ends the connection before I could make any intialization, breakpoints or start debugging request.

I thought it would only start debugging when launch or attach request is sent to debugpy. I am not sure how can I make it work.

I tried to look for any quick start guide with DAP. Can anybody help me with this?

[rchiodo]

This is the wiki we have on the topic: https://github.com/microsoft/debugpy/wiki/DAP-Client-reference, not sure if it helps. Debugpy will start an adapter process as soon as you launch it, but it should sit there waiting for stdin/stdout. How are you starting debugpy?

[gunpal5]

I am just starting the debugpy using commandline

python -m debugpy --listen localhost:4300 --wait-for-client test_calculator.py 

debugpy is sending three events:

{"seq": 1, "type": "event", "event": "output", "body": {"category": "telemetry", "output": "ptvsd", "data": {"packageVersion": "1.8.13"}}}Content-Length: 140

{"seq": 2, "type": "event", "event": "output", "body": {"category": "telemetry", "output": "debugpy", "data": {"packageVersion": "1.8.13"}}}Content-Length: 189

{"seq": 3, "type": "event", "event": "debugpySockets", "body": {"sockets": [{"host": "127.0.0.1", "port": 4300, "internal": false}, {"host": "127.0.0.1", "port": 58381, "internal": true}]}} 

after that connection is closed

[rchiodo]

You should probably turn on logging. That would list out a lot more of what debugpy is doing. --log-to-stderr should help.

[gunpal5]

Thank you, finally got it working, commandline argument --log-to-stderr is not working with ```-m debugpy --log-to-stderr". however if you run "python debugpy/adapter" then its writing the logs on console.

there was some issue with serializer, after fixing that, its working like it should.