"Reload window" breaks EH debugging

[weinand]

VS Code Insider (1.26):

• use the "Hello World" extension.
• F5
• in the new window do a "Reload Window"

Observe:

• extension reloads
• VS Code restarts debug session
• after 10 seconds this message appears:
  

Analysis:
I tried to reproduce this when running out of source, but I couldn't.
This makes me think that the problem is a timing issue.

Looking at the dev tools console and our own debug console has some evidence that supports this hypothesis:

Explanation:

EH Debugging assigns debug port 8790 for the debug session (and the idea is that the EH continues to use this port even after being restarted).
However the dev tools console shows that the restarted EH listens on port 8791 after the "reload window".

This means that it could not open port 8790 and picked the next available: 8791.
The reason why 8790 is not available is probably because 8790 is still in use because the EH is still running. I haven't seen this behaviour in EH debugging before, but it could be a new feature of the updated node.js version we are using.

The consequence of this is that VS Code tries to attach (again) to port 8790 instead of 8791 which results is the broken EH experience.

And this is probably the deeper issue behind #55916 and #55025.

I do not yet know what exactly has changed and I do not have a fix.

/cc @bpasero @roblourens any ideas?

[bpasero]

I can reproduce but I do not have an explanation for this behaviour. All I know is that I had to remove our various usages of --debug with --inspect in scripts and code.

We should probably treat this with higher priority to see if we can fix it for our upcoming release. I am sure our devs often reload windows and would get frustrated quickly.

/cc @Tyriar

[roblourens]

I can't repro, someone set "trace": true and send me logs?

[weinand]

@bpasero replacing --debug with --inspect is independent from EH debugging because EH debugging only works for --inspect for quite some time.

@alexandrudima your C++ code for fixing the exit/flushing problem of Electron node versions < 8.0 is still in, correct? But you are not aware of any problems of this code in node versions >= 8.0?

[Tyriar]

Should this have the candidate/milestone set to increase visibility? Would this block the release?

[weinand]

Yes, I've added the label/milestone.

[roblourens]

I still can't repro it. I don't think this is a candidate, if it is then surely #55916 should be.

[weinand]

I'm pretty sure that #55916 and #55955 are the same.

@roblourens here is the trace:
vscode-node-debug2.txt.zip

The problem with the trace is that it only contains info from the first EH.

[roblourens]

I don't think that's from the first EH. It shows the same thing that the log in #55899 shows, the DA attached and sent "initialized", and vscode never sent configuration requests.

[roblourens]

This seems the same as #55899, if Reload Window is basically the same case as openFolder. I can only repro this one on windows too.