Agent mode fails to see command output if output pauses for more than 1 second

[tsbertalan]

I think this might be the real cause of #7553. On ...

• Powershell v5.1.22621.4391
• GitHub Copilot extension v1.338.0
• GitHub Copilot Chat extension v0.28.5
• vscode:

Version: 1.101.2 (user setup)
Commit: 2901c5ac6db8a986a5666c3af51ff804d05af0d4
Date: 2025-06-24T20:27:15.391Z
Electron: 35.5.1
ElectronBuildId: 11727614
Chromium: 134.0.6998.205
Node.js: 22.15.1
V8: 13.4.114.21-electron.0
OS: Windows_NT x64 10.0.22631

...

I find I can ask chat (in Agent mode, with GPT-4.1) to execute

Start-Sleep -Milliseconds 950; Write-Output (Get-Random)

or

Start-Sleep -Milliseconds 1050; Write-Output (Get-Random)

and the chat will robustly be able to tell me the first random number, but not the second. Both execute fine and I can see the outputs myself. This is not a matter of the length of the output. Get-ChildItem -Recurse produces 1,110 lines of output, but the chat is able to read back to me the last line correctly.

It appears that the command tool doesn't actually wait for the command to complete (process closed, or terminal control returned, or however that is defined), but instead just waits for output to pause for 1 second, which is a bonkers assumption IMHO--I would say most of my terminal commands include a second or more of dead air.

Hovering over the octocat icon in my list of terminals shows this info:

Copilot

Process ID (PID): 24312

Command line: C:\WINDOWS\System32\WindowsPowerShell\v1.0\powershell.exe -noexit -command 'try { . "c:\Users\tbertala\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\contrib\terminal\common\scripts\shellIntegration.ps1" } catch {}'

The following extensions have contributed to this terminal's environment:

Git: Enables the following features: git auth provider
GitHub Copilot Chat: Enables use of the copilot-debug command in the terminal.
Shell integration: Rich

Seen sequences: P, A, B, E, C, D
Prompt input: |
Show Environment Contributions
Hide Details

Where I would guess that Shell integration: Rich indicates that shell integration (which might provide proper command completion telemetry) ius active.

[tsbertalan]

At the very least, it would be nice for this timeout to be configurable, instead of the #7553 workaround of telling the chat to tee all commands to disk for reading with another tool.

[tsbertalan]

Huh, I see this issue got created at vscode instead of vscode-copilot-release. I don't know why; I opened the wizard at the latter. I've updated my issue links to 7553 to be explicit.