Debug does not save launch.json before starting

[MarByteBeep]

Issue Type: Bug

I have "Save before start" enabled in the config, yet it doesn't seem to notice the saved changes until I run the app again. Steps to repro:

• change launch.json
• press F5
• observe that the changes are not in effect
• press F5 again
• changes are now in effect

Manually saving the launch.json before hitting F5 does seem to work. The weird thing is that in both cases the physical file was updated correctly. Somehow VS still uses the older version (cached?) when using "Save before start".

VS Code version: Code 1.56.2 (054a929, 2021-05-12T17:13:13.157Z)
OS version: Windows_NT x64 10.0.19042

[isidorn]

I agree that we do not automatically save launch.json before debug starts. The reason for this is that we simply first need to have a launch configuration before debugging starts and thus we save.
I will leave this open for now and we might fix it in the future.
Strangely you are the first user to find this limitation.

[MarByteBeep]

Thanks! Well the weird thing is that it actually was saved upon hitting F5, however the debug session still uses the earlier version. It's indeed very strange that no-one noticed this before, unless of course it used to work fine and got broken recently. Thanks for your reply!

[isidorn]

Yeah, I think it was never working... I do agree it is a bit strange and can be confusing. We should fix.

[asafmanor]

Hi. Having this problem as well. I believe it started a few months ago - before that, there was no need to double press the debug button in order for it to update.

[weinand]

@isidorn is it really necessary to "save" the launch.json before starting a debug session?
VS Code should be able to pick up the latest version of it without having it to read from disk, correct?

[MarByteBeep]

@asafmanor exactly, I'm pretty sure I've been using this for months and I would've noticed this problem earlier if it never worked properly. I think this got broken recently.

[weinand]

@isidorn has something changed in this area for the "restart" fix?

[isidorn]

No, nothing changed here from our side.
We are reading the configuration here https://github.com/microsoft/vscode/blob/main/src/vs/workbench/contrib/debug/browser/debugCommands.ts#L394

So the solution would be to trigger another save before we read the configuration. Unfortunetly this does not work nicely without a timeout since it takes some time for the configurationService to pick up the change.
Or that we lazily read the configuration. To lazily read the configuration is a bigger refactoring.

Users that know this was working before can you please let me know in what vscode version was this working?