microsoft
WSL 2.5+ slows dotnet when attaching debugger
Windows Version
Microsoft Windows [Version 10.0.26100.3624]
WSL Version
2.6.0.0
Are you using WSL 1 or WSL 2?
- [x] WSL 2
- [ ] WSL 1
Kernel Version
No response
Distro Version
Ubuntu 24.04
Other Software
dotnet 8 vscode (vsdbg) netcoredbg
Repro Steps
- Start WSL2
- Start a rather large dotnet8 application
- Attach a debugger, either vsdbg via VScode WSL or netcoredbg
Expected Behavior
The application should run smoothly or just about the same as before the debugger was attached.
Actual Behavior
The application is about 100x slower (literally) after the debugger is attached.
Diagnostic Logs
acl.txt appxpackage.txt bcdedit.txt HKCU.txt HKLM.txt optional-components.txt P9NP.txt windows-version.txt Winsock2.txt wpr.txt wslservice.txt wslsupport-impl.txt wslsupport-proxy.txt
WslLogs-2025-07-03_10-13-54.zip
Logs are required for review from WSL team
If this a feature request, please reply with '/feature'. If this is a question, reply with '/question'. Otherwise please attach logs by following the instructions below, your issue will not be reviewed unless they are added. These logs will help us understand what is going on in your machine.
How to collect WSL logs
Download and execute collect-wsl-logs.ps1 in an administrative powershell prompt:
Invoke-WebRequest -UseBasicParsing "https://raw.githubusercontent.com/microsoft/WSL/master/diagnostics/collect-wsl-logs.ps1" -OutFile collect-wsl-logs.ps1
Set-ExecutionPolicy Bypass -Scope Process -Force
.\collect-wsl-logs.ps1
The script will output the path of the log file once done.
If this is a networking issue, please use collect-networking-logs.ps1, following the instructions here
Once completed please upload the output files to this Github issue.
Click here for more info on logging If you choose to email these logs instead of attaching to the bug, please send them to [email protected] with the number of the github issue in the subject, and in the message a link to your comment in the github issue and reply with '/emailed-logs'.
![github-actions[bot] avatar](https://avatars.githubusercontent.com/in/15368?v=4 "Published by a pub.dev verified publisher"){kind=small}
Workaround: download and install WSL 2.4.13 from https://github.com/microsoft/WSL/releases, no uninstall needed.
@sgqkmd: I don't see the .etl file in the logs you shared. Can you share the .zip that the log script generates ?
/logs
@sgqkmd: I don't see the .etl file in the logs you shared. Can you share the .zip that the log script generates ?
/logs
Done
Diagnostic information
Issue was edited and new log file was found: https://github.com/user-attachments/files/23015229/WslLogs-2025-07-03_10-13-54.zip
Detected appx version: 2.6.0.0
I have the same problem with C++ projects. In some cases debugging is practically impossible since each 'step' takes 30s or more to refresh the local variable view. Running WSL 2.6.1
