From 4994ac165c6c7cd8a59e4528846fd56c604a7f6d Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 16:08:35 +0100
Subject: [PATCH 1/8] Add Windows debugging scripts for flaky stdio test

Add PowerShell scripts to help debug test_stdio_context_manager_exiting
flakiness on Windows with Python 3.11/3.12:

- check-tee-command.ps1: Verify tee command availability
- test-stdio-flakiness-200-runs.ps1: Run test 200 times for statistics
- test-stdio-flakiness-until-failure.ps1: Run until failure occurs
- test-stdio-verbose-debug.ps1: Single run with maximum debug output
- README.md: Documentation for using the scripts
---
 scripts/windows-debug/README.md               |  55 ++++++++++
 scripts/windows-debug/check-tee-command.ps1   | 101 ++++++++++++++++++
 .../test-stdio-flakiness-200-runs.ps1         |  44 ++++++++
 .../test-stdio-flakiness-until-failure.ps1    |  42 ++++++++
 .../test-stdio-verbose-debug.ps1              |  40 +++++++
 5 files changed, 282 insertions(+)
 create mode 100644 scripts/windows-debug/README.md
 create mode 100644 scripts/windows-debug/check-tee-command.ps1
 create mode 100644 scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
 create mode 100644 scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
 create mode 100644 scripts/windows-debug/test-stdio-verbose-debug.ps1

diff --git a/scripts/windows-debug/README.md b/scripts/windows-debug/README.md
new file mode 100644
index 0000000000..378b7d0e8f
--- /dev/null
+++ b/scripts/windows-debug/README.md
@@ -0,0 +1,55 @@
+# Windows Test Debugging Scripts
+
+This folder contains PowerShell scripts to help debug the flaky `test_stdio_context_manager_exiting` test on Windows with Python 3.11/3.12.
+
+## Prerequisites
+
+- Windows PowerShell or PowerShell Core
+- Python 3.11 or 3.12
+- `uv` installed and configured
+- Virtual environment activated
+
+## Scripts
+
+### 1. `check-tee-command.ps1`
+Checks if the `tee` command is available on your Windows system. The test requires `tee` to run.
+
+```powershell
+.\check-tee-command.ps1
+```
+
+### 2. `test-stdio-flakiness-200-runs.ps1`
+Runs the test 200 times and reports the failure rate.
+
+```powershell
+.\test-stdio-flakiness-200-runs.ps1
+```
+
+### 3. `test-stdio-flakiness-until-failure.ps1`
+Runs the test in a loop until it fails, useful for catching intermittent failures.
+
+```powershell
+.\test-stdio-flakiness-until-failure.ps1
+```
+
+### 4. `test-stdio-verbose-debug.ps1`
+Runs the test once with maximum debugging output enabled.
+
+```powershell
+.\test-stdio-verbose-debug.ps1
+```
+
+## Usage Notes
+
+1. Make sure your virtual environment is activated before running these scripts
+2. Run scripts from the repository root directory
+3. If scripts fail with execution policy errors, run:
+   ```powershell
+   Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
+   ```
+
+## Interpreting Results
+
+- If `tee` is not available, the test will be skipped
+- Flaky failures typically show up as timeout errors or process cleanup issues
+- Look for patterns in failure output, especially around process termination timing
\ No newline at end of file
diff --git a/scripts/windows-debug/check-tee-command.ps1 b/scripts/windows-debug/check-tee-command.ps1
new file mode 100644
index 0000000000..68d83bb225
--- /dev/null
+++ b/scripts/windows-debug/check-tee-command.ps1
@@ -0,0 +1,101 @@
+#!/usr/bin/env pwsh
+# Script to check if tee command is available on Windows
+# Usage: .\check-tee-command.ps1
+
+Write-Host "Checking for 'tee' command availability on Windows..." -ForegroundColor Cyan
+Write-Host ""
+
+# Method 1: Using where.exe
+Write-Host "Method 1: Using where.exe" -ForegroundColor Yellow
+try {
+    $whereResult = where.exe tee 2>&1
+    if ($LASTEXITCODE -eq 0) {
+        Write-Host "  Found tee at: $whereResult" -ForegroundColor Green
+    } else {
+        Write-Host "  tee not found via where.exe" -ForegroundColor Red
+    }
+} catch {
+    Write-Host "  Error checking with where.exe: $_" -ForegroundColor Red
+}
+
+Write-Host ""
+
+# Method 2: Using Get-Command
+Write-Host "Method 2: Using Get-Command" -ForegroundColor Yellow
+try {
+    $getCommandResult = Get-Command tee -ErrorAction Stop
+    Write-Host "  Found tee:" -ForegroundColor Green
+    Write-Host "    Name: $($getCommandResult.Name)"
+    Write-Host "    CommandType: $($getCommandResult.CommandType)"
+    Write-Host "    Source: $($getCommandResult.Source)"
+    Write-Host "    Version: $($getCommandResult.Version)"
+} catch {
+    Write-Host "  tee not found via Get-Command" -ForegroundColor Red
+}
+
+Write-Host ""
+
+# Method 3: Check common locations
+Write-Host "Method 3: Checking common locations" -ForegroundColor Yellow
+$commonPaths = @(
+    "C:\Program Files\Git\usr\bin\tee.exe",
+    "C:\Program Files (x86)\Git\usr\bin\tee.exe",
+    "C:\tools\msys64\usr\bin\tee.exe",
+    "C:\msys64\usr\bin\tee.exe",
+    "C:\cygwin64\bin\tee.exe",
+    "C:\cygwin\bin\tee.exe"
+)
+
+$found = $false
+foreach ($path in $commonPaths) {
+    if (Test-Path $path) {
+        Write-Host "  Found at: $path" -ForegroundColor Green
+        $found = $true
+    }
+}
+
+if (-not $found) {
+    Write-Host "  tee not found in common locations" -ForegroundColor Red
+}
+
+Write-Host ""
+
+# Method 4: Check if it's a PowerShell alias
+Write-Host "Method 4: Checking PowerShell aliases" -ForegroundColor Yellow
+$alias = Get-Alias tee -ErrorAction SilentlyContinue
+if ($alias) {
+    Write-Host "  Found PowerShell alias:" -ForegroundColor Green
+    Write-Host "    Name: $($alias.Name)"
+    Write-Host "    Definition: $($alias.Definition)"
+} else {
+    Write-Host "  No PowerShell alias for tee" -ForegroundColor Yellow
+}
+
+Write-Host ""
+
+# Method 5: Python check (what the test uses)
+Write-Host "Method 5: Python shutil.which() check" -ForegroundColor Yellow
+$pythonCheck = python -c "import shutil; print(shutil.which('tee'))"
+if ($pythonCheck -and $pythonCheck -ne "None") {
+    Write-Host "  Python found tee at: $pythonCheck" -ForegroundColor Green
+} else {
+    Write-Host "  Python shutil.which() did not find tee" -ForegroundColor Red
+}
+
+Write-Host ""
+Write-Host "========== SUMMARY ==========" -ForegroundColor Cyan
+if ($whereResult -or $getCommandResult -or $found -or ($pythonCheck -and $pythonCheck -ne "None")) {
+    Write-Host "tee command is available" -ForegroundColor Green
+    Write-Host ""
+    Write-Host "The test_stdio_context_manager_exiting test should run." -ForegroundColor Green
+} else {
+    Write-Host "tee command is NOT available" -ForegroundColor Red
+    Write-Host ""
+    Write-Host "The test_stdio_context_manager_exiting test will be SKIPPED." -ForegroundColor Yellow
+    Write-Host ""
+    Write-Host "To install tee on Windows, you can:" -ForegroundColor Cyan
+    Write-Host "  1. Install Git for Windows (includes tee in Git Bash)"
+    Write-Host "  2. Install WSL (Windows Subsystem for Linux)"
+    Write-Host "  3. Install MSYS2 or Cygwin"
+    Write-Host "  4. Use PowerShell's Tee-Object cmdlet (different syntax)"
+}
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1 b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
new file mode 100644
index 0000000000..691f4aac28
--- /dev/null
+++ b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
@@ -0,0 +1,44 @@
+#!/usr/bin/env pwsh
+# Script to run test_stdio_context_manager_exiting 200 times to detect flakiness
+# Usage: .\test-stdio-flakiness-200-runs.ps1
+
+Write-Host "Running test_stdio_context_manager_exiting 200 times to detect flakiness..." -ForegroundColor Cyan
+Write-Host "Test: tests/client/test_stdio.py::test_stdio_context_manager_exiting" -ForegroundColor Yellow
+Write-Host ""
+
+$startTime = Get-Date
+$count = 0
+$failures = 0
+$failedRuns = @()
+
+for ($i = 1; $i -le 200; $i++) {
+    Write-Host "Run $i of 200..." -NoNewline
+    
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs 2>&1
+    $exitCode = $LASTEXITCODE
+    
+    if ($exitCode -ne 0) {
+        $failures++
+        $failedRuns += $i
+        Write-Host " FAILED" -ForegroundColor Red
+        Write-Host "Failure output:" -ForegroundColor Red
+        Write-Host $output
+        Write-Host ""
+    } else {
+        Write-Host " PASSED" -ForegroundColor Green
+    }
+}
+
+$endTime = Get-Date
+$duration = $endTime - $startTime
+
+Write-Host ""
+Write-Host "========== SUMMARY ==========" -ForegroundColor Cyan
+Write-Host "Total runs: 200"
+Write-Host "Successful runs: $($count - $failures)" -ForegroundColor Green
+Write-Host "Failed runs: $failures" -ForegroundColor Red
+if ($failures -gt 0) {
+    Write-Host "Failed on runs: $($failedRuns -join ', ')" -ForegroundColor Red
+}
+Write-Host "Duration: $($duration.ToString())"
+Write-Host "Failure rate: $([math]::Round(($failures / 200) * 100, 2))%"
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1 b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
new file mode 100644
index 0000000000..66b705aa4d
--- /dev/null
+++ b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
@@ -0,0 +1,42 @@
+#!/usr/bin/env pwsh
+# Script to run test_stdio_context_manager_exiting until it fails
+# Usage: .\test-stdio-flakiness-until-failure.ps1
+
+Write-Host "Running test_stdio_context_manager_exiting until failure..." -ForegroundColor Cyan
+Write-Host "Test: tests/client/test_stdio.py::test_stdio_context_manager_exiting" -ForegroundColor Yellow
+Write-Host "Press Ctrl+C to stop" -ForegroundColor Gray
+Write-Host ""
+
+$startTime = Get-Date
+$i = 0
+
+while ($true) {
+    $i++
+    Write-Host "Run $i..." -NoNewline
+    
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs 2>&1
+    $exitCode = $LASTEXITCODE
+    
+    if ($exitCode -ne 0) {
+        $endTime = Get-Date
+        $duration = $endTime - $startTime
+        
+        Write-Host " FAILED!" -ForegroundColor Red
+        Write-Host ""
+        Write-Host "========== FAILURE DETECTED ==========" -ForegroundColor Red
+        Write-Host "Failed on run: $i" -ForegroundColor Red
+        Write-Host "Time until failure: $($duration.ToString())" -ForegroundColor Yellow
+        Write-Host ""
+        Write-Host "Failure output:" -ForegroundColor Red
+        Write-Host $output
+        break
+    } else {
+        Write-Host " PASSED" -ForegroundColor Green
+    }
+    
+    # Small delay to prevent overwhelming the system
+    Start-Sleep -Milliseconds 100
+}
+
+Write-Host ""
+Write-Host "Exiting after failure detection." -ForegroundColor Cyan
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-verbose-debug.ps1 b/scripts/windows-debug/test-stdio-verbose-debug.ps1
new file mode 100644
index 0000000000..0e5622779c
--- /dev/null
+++ b/scripts/windows-debug/test-stdio-verbose-debug.ps1
@@ -0,0 +1,40 @@
+#!/usr/bin/env pwsh
+# Script to run test_stdio_context_manager_exiting with maximum debugging output
+# Usage: .\test-stdio-verbose-debug.ps1
+
+Write-Host "Running test_stdio_context_manager_exiting with verbose debug output..." -ForegroundColor Cyan
+Write-Host ""
+
+# Set environment variables for debugging
+$env:PYTHONFAULTHANDLER = "1"
+$env:PYTEST_CURRENT_TEST = "1"
+
+Write-Host "Environment variables set:" -ForegroundColor Yellow
+Write-Host "  PYTHONFAULTHANDLER = 1 (enables Python fault handler)"
+Write-Host ""
+
+Write-Host "Running test with maximum verbosity..." -ForegroundColor Cyan
+Write-Host ""
+
+# Run the test with all debugging options
+uv run --frozen pytest `
+    tests/client/test_stdio.py::test_stdio_context_manager_exiting `
+    -xvs `
+    --log-cli-level=DEBUG `
+    --log-cli-format="%(asctime)s [%(levelname)s] %(name)s: %(message)s" `
+    --capture=no `
+    --tb=long `
+    --full-trace
+
+$exitCode = $LASTEXITCODE
+
+Write-Host ""
+if ($exitCode -eq 0) {
+    Write-Host "Test PASSED" -ForegroundColor Green
+} else {
+    Write-Host "Test FAILED with exit code: $exitCode" -ForegroundColor Red
+}
+
+# Clean up environment variables
+Remove-Item Env:PYTHONFAULTHANDLER -ErrorAction SilentlyContinue
+Remove-Item Env:PYTEST_CURRENT_TEST -ErrorAction SilentlyContinue
\ No newline at end of file

From 154ef9c6bca527c4ee51ad1bfa5890e95a351c55 Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 16:15:17 +0100
Subject: [PATCH 2/8] Fix pytest-xdist issue in Windows debug scripts

Add -n 0 flag to disable xdist parallel execution which was causing
test collection failures. Also fix successful run count calculation.
---
 scripts/windows-debug/test-stdio-flakiness-200-runs.ps1      | 4 ++--
 scripts/windows-debug/test-stdio-flakiness-until-failure.ps1 | 2 +-
 scripts/windows-debug/test-stdio-verbose-debug.ps1           | 1 +
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1 b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
index 691f4aac28..5d30c2e070 100644
--- a/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
+++ b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
@@ -14,7 +14,7 @@ $failedRuns = @()
 for ($i = 1; $i -le 200; $i++) {
     Write-Host "Run $i of 200..." -NoNewline
     
-    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs 2>&1
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -n 0 2>&1
     $exitCode = $LASTEXITCODE
     
     if ($exitCode -ne 0) {
@@ -35,7 +35,7 @@ $duration = $endTime - $startTime
 Write-Host ""
 Write-Host "========== SUMMARY ==========" -ForegroundColor Cyan
 Write-Host "Total runs: 200"
-Write-Host "Successful runs: $($count - $failures)" -ForegroundColor Green
+Write-Host "Successful runs: $(200 - $failures)" -ForegroundColor Green
 Write-Host "Failed runs: $failures" -ForegroundColor Red
 if ($failures -gt 0) {
     Write-Host "Failed on runs: $($failedRuns -join ', ')" -ForegroundColor Red
diff --git a/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1 b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
index 66b705aa4d..8724502b37 100644
--- a/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
+++ b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
@@ -14,7 +14,7 @@ while ($true) {
     $i++
     Write-Host "Run $i..." -NoNewline
     
-    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs 2>&1
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -n 0 2>&1
     $exitCode = $LASTEXITCODE
     
     if ($exitCode -ne 0) {
diff --git a/scripts/windows-debug/test-stdio-verbose-debug.ps1 b/scripts/windows-debug/test-stdio-verbose-debug.ps1
index 0e5622779c..29f47ff7da 100644
--- a/scripts/windows-debug/test-stdio-verbose-debug.ps1
+++ b/scripts/windows-debug/test-stdio-verbose-debug.ps1
@@ -20,6 +20,7 @@ Write-Host ""
 uv run --frozen pytest `
     tests/client/test_stdio.py::test_stdio_context_manager_exiting `
     -xvs `
+    -n 0 `
     --log-cli-level=DEBUG `
     --log-cli-format="%(asctime)s [%(levelname)s] %(name)s: %(message)s" `
     --capture=no `

From 781367c52c60edf8ba4b13e3e0d1a28906b6fc92 Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 16:17:14 +0100
Subject: [PATCH 3/8] Fix xdist issue with multiple approaches

- Use PYTEST_DISABLE_PLUGIN_AUTOLOAD environment variable (recommended in CLAUDE.md)
- Use -p no:xdist flag to explicitly disable the plugin
- Add --no-cov to avoid coverage plugin issues
- Add test-stdio-simple.ps1 to try different methods of disabling xdist
---
 .../test-stdio-flakiness-200-runs.ps1         | 13 ++++-
 .../test-stdio-flakiness-until-failure.ps1    | 13 ++++-
 scripts/windows-debug/test-stdio-simple.ps1   | 54 +++++++++++++++++++
 .../test-stdio-verbose-debug.ps1              |  9 +++-
 4 files changed, 83 insertions(+), 6 deletions(-)
 create mode 100644 scripts/windows-debug/test-stdio-simple.ps1

diff --git a/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1 b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
index 5d30c2e070..54df0c9a12 100644
--- a/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
+++ b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
@@ -6,6 +6,9 @@ Write-Host "Running test_stdio_context_manager_exiting 200 times to detect flaki
 Write-Host "Test: tests/client/test_stdio.py::test_stdio_context_manager_exiting" -ForegroundColor Yellow
 Write-Host ""
 
+# Disable pytest plugin autoload to avoid xdist issues
+$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
+
 $startTime = Get-Date
 $count = 0
 $failures = 0
@@ -14,7 +17,10 @@ $failedRuns = @()
 for ($i = 1; $i -le 200; $i++) {
     Write-Host "Run $i of 200..." -NoNewline
     
-    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -n 0 2>&1
+    $output = & {
+        $env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
+        uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs --no-cov -p no:xdist 2>&1
+    }
     $exitCode = $LASTEXITCODE
     
     if ($exitCode -ne 0) {
@@ -41,4 +47,7 @@ if ($failures -gt 0) {
     Write-Host "Failed on runs: $($failedRuns -join ', ')" -ForegroundColor Red
 }
 Write-Host "Duration: $($duration.ToString())"
-Write-Host "Failure rate: $([math]::Round(($failures / 200) * 100, 2))%"
\ No newline at end of file
+Write-Host "Failure rate: $([math]::Round(($failures / 200) * 100, 2))%"
+
+# Clean up environment variable
+Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1 b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
index 8724502b37..4c0e047414 100644
--- a/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
+++ b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
@@ -7,6 +7,9 @@ Write-Host "Test: tests/client/test_stdio.py::test_stdio_context_manager_exiting
 Write-Host "Press Ctrl+C to stop" -ForegroundColor Gray
 Write-Host ""
 
+# Disable pytest plugin autoload to avoid xdist issues
+$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
+
 $startTime = Get-Date
 $i = 0
 
@@ -14,7 +17,10 @@ while ($true) {
     $i++
     Write-Host "Run $i..." -NoNewline
     
-    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -n 0 2>&1
+    $output = & {
+        $env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
+        uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs --no-cov -p no:xdist 2>&1
+    }
     $exitCode = $LASTEXITCODE
     
     if ($exitCode -ne 0) {
@@ -39,4 +45,7 @@ while ($true) {
 }
 
 Write-Host ""
-Write-Host "Exiting after failure detection." -ForegroundColor Cyan
\ No newline at end of file
+Write-Host "Exiting after failure detection." -ForegroundColor Cyan
+
+# Clean up environment variable
+Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-simple.ps1 b/scripts/windows-debug/test-stdio-simple.ps1
new file mode 100644
index 0000000000..d249703c42
--- /dev/null
+++ b/scripts/windows-debug/test-stdio-simple.ps1
@@ -0,0 +1,54 @@
+#!/usr/bin/env pwsh
+# Simple script to run the test without xdist
+# Usage: .\test-stdio-simple.ps1
+
+Write-Host "Running test_stdio_context_manager_exiting with xdist disabled..." -ForegroundColor Cyan
+Write-Host ""
+
+# Method 1: Using environment variable (recommended in CLAUDE.md)
+Write-Host "Method 1: Using PYTEST_DISABLE_PLUGIN_AUTOLOAD environment variable" -ForegroundColor Yellow
+$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
+uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs
+$exitCode1 = $LASTEXITCODE
+Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
+
+if ($exitCode1 -eq 0) {
+    Write-Host "Method 1: PASSED" -ForegroundColor Green
+} else {
+    Write-Host "Method 1: FAILED with exit code $exitCode1" -ForegroundColor Red
+}
+
+Write-Host ""
+
+# Method 2: Using -p no:xdist to disable the plugin
+Write-Host "Method 2: Using -p no:xdist flag" -ForegroundColor Yellow
+uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -p no:xdist
+$exitCode2 = $LASTEXITCODE
+
+if ($exitCode2 -eq 0) {
+    Write-Host "Method 2: PASSED" -ForegroundColor Green
+} else {
+    Write-Host "Method 2: FAILED with exit code $exitCode2" -ForegroundColor Red
+}
+
+Write-Host ""
+
+# Method 3: Override addopts from pyproject.toml
+Write-Host "Method 3: Overriding pytest addopts" -ForegroundColor Yellow
+uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -o addopts=""
+$exitCode3 = $LASTEXITCODE
+
+if ($exitCode3 -eq 0) {
+    Write-Host "Method 3: PASSED" -ForegroundColor Green
+} else {
+    Write-Host "Method 3: FAILED with exit code $exitCode3" -ForegroundColor Red
+}
+
+Write-Host ""
+Write-Host "========== SUMMARY ==========" -ForegroundColor Cyan
+if ($exitCode1 -eq 0 -or $exitCode2 -eq 0 -or $exitCode3 -eq 0) {
+    Write-Host "At least one method succeeded!" -ForegroundColor Green
+    Write-Host "Use the successful method in your testing."
+} else {
+    Write-Host "All methods failed. The test may have a different issue." -ForegroundColor Red
+}
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-verbose-debug.ps1 b/scripts/windows-debug/test-stdio-verbose-debug.ps1
index 29f47ff7da..9696af81eb 100644
--- a/scripts/windows-debug/test-stdio-verbose-debug.ps1
+++ b/scripts/windows-debug/test-stdio-verbose-debug.ps1
@@ -8,19 +8,23 @@ Write-Host ""
 # Set environment variables for debugging
 $env:PYTHONFAULTHANDLER = "1"
 $env:PYTEST_CURRENT_TEST = "1"
+$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
 
 Write-Host "Environment variables set:" -ForegroundColor Yellow
 Write-Host "  PYTHONFAULTHANDLER = 1 (enables Python fault handler)"
+Write-Host "  PYTEST_DISABLE_PLUGIN_AUTOLOAD = '' (disables pytest plugin autoload)"
 Write-Host ""
 
 Write-Host "Running test with maximum verbosity..." -ForegroundColor Cyan
 Write-Host ""
 
 # Run the test with all debugging options
+$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
 uv run --frozen pytest `
     tests/client/test_stdio.py::test_stdio_context_manager_exiting `
     -xvs `
-    -n 0 `
+    --no-cov `
+    -p no:xdist `
     --log-cli-level=DEBUG `
     --log-cli-format="%(asctime)s [%(levelname)s] %(name)s: %(message)s" `
     --capture=no `
@@ -38,4 +42,5 @@ if ($exitCode -eq 0) {
 
 # Clean up environment variables
 Remove-Item Env:PYTHONFAULTHANDLER -ErrorAction SilentlyContinue
-Remove-Item Env:PYTEST_CURRENT_TEST -ErrorAction SilentlyContinue
\ No newline at end of file
+Remove-Item Env:PYTEST_CURRENT_TEST -ErrorAction SilentlyContinue
+Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
\ No newline at end of file

From b0edf56111814a443b5b02edb542d175e8228112 Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 16:25:58 +0100
Subject: [PATCH 4/8] Simplify Windows debug scripts based on working solution

- Add setup-environment.ps1 to configure Git for Windows tee in PATH
- Simplify all scripts to use working -o addopts="" approach
- Add tee availability checks to all scripts
- Update README with clear setup instructions and troubleshooting
- Remove complex xdist workarounds in favor of simple override
---
 scripts/windows-debug/README.md               | 64 +++++++++++++++++--
 scripts/windows-debug/check-tee-command.ps1   | 45 ++++++++++++-
 scripts/windows-debug/setup-environment.ps1   | 59 +++++++++++++++++
 .../test-stdio-flakiness-200-runs.ps1         | 22 ++++---
 .../test-stdio-flakiness-until-failure.ps1    | 22 ++++---
 scripts/windows-debug/test-stdio-simple.ps1   | 62 +++++++-----------
 .../test-stdio-verbose-debug.ps1              | 20 ++++--
 7 files changed, 220 insertions(+), 74 deletions(-)
 create mode 100644 scripts/windows-debug/setup-environment.ps1

diff --git a/scripts/windows-debug/README.md b/scripts/windows-debug/README.md
index 378b7d0e8f..9f33eed175 100644
--- a/scripts/windows-debug/README.md
+++ b/scripts/windows-debug/README.md
@@ -8,31 +8,64 @@ This folder contains PowerShell scripts to help debug the flaky `test_stdio_cont
 - Python 3.11 or 3.12
 - `uv` installed and configured
 - Virtual environment activated
+- Git for Windows installed (provides the `tee` command)
+
+## Quick Start
+
+1. First, set up your environment to make `tee` available:
+   ```powershell
+   . .\setup-environment.ps1
+   ```
+   **Note:** The dot (.) at the beginning is important - it sources the script.
+
+2. Verify the test runs:
+   ```powershell
+   .\test-stdio-simple.ps1
+   ```
+
+3. Run the flakiness tests:
+   ```powershell
+   .\test-stdio-flakiness-200-runs.ps1
+   ```
 
 ## Scripts
 
-### 1. `check-tee-command.ps1`
+### 1. `setup-environment.ps1`
+Sets up the environment by adding Git for Windows tools to PATH. **Must be dot-sourced.**
+
+```powershell
+. .\setup-environment.ps1
+```
+
+### 2. `check-tee-command.ps1`
 Checks if the `tee` command is available on your Windows system. The test requires `tee` to run.
 
 ```powershell
 .\check-tee-command.ps1
 ```
 
-### 2. `test-stdio-flakiness-200-runs.ps1`
+### 3. `test-stdio-simple.ps1`
+Runs the test once to verify it works.
+
+```powershell
+.\test-stdio-simple.ps1
+```
+
+### 4. `test-stdio-flakiness-200-runs.ps1`
 Runs the test 200 times and reports the failure rate.
 
 ```powershell
 .\test-stdio-flakiness-200-runs.ps1
 ```
 
-### 3. `test-stdio-flakiness-until-failure.ps1`
+### 5. `test-stdio-flakiness-until-failure.ps1`
 Runs the test in a loop until it fails, useful for catching intermittent failures.
 
 ```powershell
 .\test-stdio-flakiness-until-failure.ps1
 ```
 
-### 4. `test-stdio-verbose-debug.ps1`
+### 6. `test-stdio-verbose-debug.ps1`
 Runs the test once with maximum debugging output enabled.
 
 ```powershell
@@ -42,8 +75,9 @@ Runs the test once with maximum debugging output enabled.
 ## Usage Notes
 
 1. Make sure your virtual environment is activated before running these scripts
-2. Run scripts from the repository root directory
-3. If scripts fail with execution policy errors, run:
+2. Always run `setup-environment.ps1` first in each new PowerShell session
+3. Run scripts from the `scripts\windows-debug` directory
+4. If scripts fail with execution policy errors, run:
    ```powershell
    Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
    ```
@@ -52,4 +86,20 @@ Runs the test once with maximum debugging output enabled.
 
 - If `tee` is not available, the test will be skipped
 - Flaky failures typically show up as timeout errors or process cleanup issues
-- Look for patterns in failure output, especially around process termination timing
\ No newline at end of file
+- Look for patterns in failure output, especially around process termination timing
+
+## Troubleshooting
+
+### "tee command not found"
+1. Install Git for Windows from https://gitforwindows.org/
+2. Run `. .\setup-environment.ps1` to add Git tools to PATH
+3. Verify with `python -c "import shutil; print(shutil.which('tee'))"`
+
+### "no tests ran" with xdist
+The scripts now use `-o addopts=""` to override the pytest configuration that enables xdist by default.
+
+### Making PATH changes permanent
+Add this line to your PowerShell profile:
+```powershell
+$env:PATH = "C:\Program Files\Git\usr\bin;$env:PATH"
+```
\ No newline at end of file
diff --git a/scripts/windows-debug/check-tee-command.ps1 b/scripts/windows-debug/check-tee-command.ps1
index 68d83bb225..46fa7f093e 100644
--- a/scripts/windows-debug/check-tee-command.ps1
+++ b/scripts/windows-debug/check-tee-command.ps1
@@ -5,6 +5,9 @@
 Write-Host "Checking for 'tee' command availability on Windows..." -ForegroundColor Cyan
 Write-Host ""
 
+# Store original PATH
+$originalPath = $env:PATH
+
 # Method 1: Using where.exe
 Write-Host "Method 1: Using where.exe" -ForegroundColor Yellow
 try {
@@ -82,12 +85,47 @@ if ($pythonCheck -and $pythonCheck -ne "None") {
     Write-Host "  Python shutil.which() did not find tee" -ForegroundColor Red
 }
 
+Write-Host ""
+
+# Method 6: Try adding Git for Windows to PATH if it exists
+Write-Host "Method 6: Adding Git for Windows to PATH temporarily" -ForegroundColor Yellow
+$gitPaths = @(
+    "C:\Program Files\Git\usr\bin",
+    "C:\Program Files (x86)\Git\usr\bin"
+)
+
+$addedToPath = $false
+foreach ($gitPath in $gitPaths) {
+    if (Test-Path $gitPath) {
+        Write-Host "  Found Git directory: $gitPath" -ForegroundColor Green
+        $env:PATH = "$gitPath;$env:PATH"
+        $teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+        if ($teeCheck -and $teeCheck -ne "None") {
+            Write-Host "  tee is now available at: $teeCheck" -ForegroundColor Green
+            $addedToPath = $true
+            break
+        }
+    }
+}
+
+if (-not $addedToPath) {
+    # Restore original PATH if we didn't find tee
+    $env:PATH = $originalPath
+    Write-Host "  Could not add Git for Windows tee to PATH" -ForegroundColor Red
+}
+
 Write-Host ""
 Write-Host "========== SUMMARY ==========" -ForegroundColor Cyan
-if ($whereResult -or $getCommandResult -or $found -or ($pythonCheck -and $pythonCheck -ne "None")) {
+if ($whereResult -or $getCommandResult -or $found -or ($pythonCheck -and $pythonCheck -ne "None") -or $addedToPath) {
     Write-Host "tee command is available" -ForegroundColor Green
     Write-Host ""
     Write-Host "The test_stdio_context_manager_exiting test should run." -ForegroundColor Green
+    if ($addedToPath) {
+        Write-Host ""
+        Write-Host "Note: Git for Windows tee was added to PATH for this session." -ForegroundColor Yellow
+        Write-Host "To make this permanent, add this to your PowerShell profile:" -ForegroundColor Yellow
+        Write-Host "  `$env:PATH = `"C:\Program Files\Git\usr\bin;`$env:PATH`"" -ForegroundColor Cyan
+    }
 } else {
     Write-Host "tee command is NOT available" -ForegroundColor Red
     Write-Host ""
@@ -98,4 +136,7 @@ if ($whereResult -or $getCommandResult -or $found -or ($pythonCheck -and $python
     Write-Host "  2. Install WSL (Windows Subsystem for Linux)"
     Write-Host "  3. Install MSYS2 or Cygwin"
     Write-Host "  4. Use PowerShell's Tee-Object cmdlet (different syntax)"
-}
\ No newline at end of file
+}
+
+# Restore original PATH
+$env:PATH = $originalPath
\ No newline at end of file
diff --git a/scripts/windows-debug/setup-environment.ps1 b/scripts/windows-debug/setup-environment.ps1
new file mode 100644
index 0000000000..25dd44e27c
--- /dev/null
+++ b/scripts/windows-debug/setup-environment.ps1
@@ -0,0 +1,59 @@
+#!/usr/bin/env pwsh
+# Script to set up the environment for running stdio tests on Windows
+# This adds Git for Windows tools to PATH if available
+# Usage: . .\setup-environment.ps1 (note the dot-sourcing)
+
+Write-Host "Setting up environment for stdio tests..." -ForegroundColor Cyan
+Write-Host ""
+
+# Check if Git for Windows is installed
+$gitPaths = @(
+    "C:\Program Files\Git\usr\bin",
+    "C:\Program Files (x86)\Git\usr\bin"
+)
+
+$gitFound = $false
+$gitPath = ""
+
+foreach ($path in $gitPaths) {
+    if (Test-Path $path) {
+        $gitPath = $path
+        $gitFound = $true
+        break
+    }
+}
+
+if ($gitFound) {
+    Write-Host "Found Git for Windows at: $gitPath" -ForegroundColor Green
+    
+    # Add to PATH
+    $env:PATH = "$gitPath;$env:PATH"
+    
+    # Verify tee is available
+    $teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+    if ($teeCheck -and $teeCheck -ne "None") {
+        Write-Host "Successfully added tee to PATH: $teeCheck" -ForegroundColor Green
+        Write-Host ""
+        Write-Host "Environment is ready for stdio tests!" -ForegroundColor Green
+        Write-Host ""
+        Write-Host "You can now run the test scripts or individual tests:" -ForegroundColor Cyan
+        Write-Host "  .\test-stdio-flakiness-200-runs.ps1"
+        Write-Host "  .\test-stdio-flakiness-until-failure.ps1"
+        Write-Host "  .\test-stdio-verbose-debug.ps1"
+        Write-Host ""
+        Write-Host "Or run individual tests with:" -ForegroundColor Cyan
+        Write-Host "  uv run pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -v -o addopts="""""
+    } else {
+        Write-Host "WARNING: Git path was added but tee is still not available" -ForegroundColor Yellow
+    }
+} else {
+    Write-Host "Git for Windows not found in standard locations." -ForegroundColor Red
+    Write-Host ""
+    Write-Host "Please install Git for Windows from: https://gitforwindows.org/" -ForegroundColor Yellow
+    Write-Host "Or manually add the Git usr\bin directory to your PATH." -ForegroundColor Yellow
+}
+
+Write-Host ""
+Write-Host "Note: This only affects the current PowerShell session." -ForegroundColor Gray
+Write-Host "To make changes permanent, add to your PowerShell profile:" -ForegroundColor Gray
+Write-Host '  $env:PATH = "C:\Program Files\Git\usr\bin;$env:PATH"' -ForegroundColor Cyan
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1 b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
index 54df0c9a12..26bdddd6be 100644
--- a/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
+++ b/scripts/windows-debug/test-stdio-flakiness-200-runs.ps1
@@ -1,13 +1,21 @@
 #!/usr/bin/env pwsh
 # Script to run test_stdio_context_manager_exiting 200 times to detect flakiness
 # Usage: .\test-stdio-flakiness-200-runs.ps1
+#
+# Prerequisites: Run . .\setup-environment.ps1 first to ensure tee is available
 
 Write-Host "Running test_stdio_context_manager_exiting 200 times to detect flakiness..." -ForegroundColor Cyan
 Write-Host "Test: tests/client/test_stdio.py::test_stdio_context_manager_exiting" -ForegroundColor Yellow
 Write-Host ""
 
-# Disable pytest plugin autoload to avoid xdist issues
-$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
+# Check if tee is available
+$teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+if (-not $teeCheck -or $teeCheck -eq "None") {
+    Write-Host "ERROR: tee command not found!" -ForegroundColor Red
+    Write-Host "Please run: . .\setup-environment.ps1" -ForegroundColor Yellow
+    Write-Host "(Note the dot at the beginning to source the script)" -ForegroundColor Yellow
+    exit 1
+}
 
 $startTime = Get-Date
 $count = 0
@@ -17,10 +25,7 @@ $failedRuns = @()
 for ($i = 1; $i -le 200; $i++) {
     Write-Host "Run $i of 200..." -NoNewline
     
-    $output = & {
-        $env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
-        uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs --no-cov -p no:xdist 2>&1
-    }
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -o addopts="" 2>&1
     $exitCode = $LASTEXITCODE
     
     if ($exitCode -ne 0) {
@@ -47,7 +52,4 @@ if ($failures -gt 0) {
     Write-Host "Failed on runs: $($failedRuns -join ', ')" -ForegroundColor Red
 }
 Write-Host "Duration: $($duration.ToString())"
-Write-Host "Failure rate: $([math]::Round(($failures / 200) * 100, 2))%"
-
-# Clean up environment variable
-Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
\ No newline at end of file
+Write-Host "Failure rate: $([math]::Round(($failures / 200) * 100, 2))%"
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1 b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
index 4c0e047414..1a9df0e403 100644
--- a/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
+++ b/scripts/windows-debug/test-stdio-flakiness-until-failure.ps1
@@ -1,14 +1,22 @@
 #!/usr/bin/env pwsh
 # Script to run test_stdio_context_manager_exiting until it fails
 # Usage: .\test-stdio-flakiness-until-failure.ps1
+#
+# Prerequisites: Run . .\setup-environment.ps1 first to ensure tee is available
 
 Write-Host "Running test_stdio_context_manager_exiting until failure..." -ForegroundColor Cyan
 Write-Host "Test: tests/client/test_stdio.py::test_stdio_context_manager_exiting" -ForegroundColor Yellow
 Write-Host "Press Ctrl+C to stop" -ForegroundColor Gray
 Write-Host ""
 
-# Disable pytest plugin autoload to avoid xdist issues
-$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
+# Check if tee is available
+$teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+if (-not $teeCheck -or $teeCheck -eq "None") {
+    Write-Host "ERROR: tee command not found!" -ForegroundColor Red
+    Write-Host "Please run: . .\setup-environment.ps1" -ForegroundColor Yellow
+    Write-Host "(Note the dot at the beginning to source the script)" -ForegroundColor Yellow
+    exit 1
+}
 
 $startTime = Get-Date
 $i = 0
@@ -17,10 +25,7 @@ while ($true) {
     $i++
     Write-Host "Run $i..." -NoNewline
     
-    $output = & {
-        $env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
-        uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs --no-cov -p no:xdist 2>&1
-    }
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -o addopts="" 2>&1
     $exitCode = $LASTEXITCODE
     
     if ($exitCode -ne 0) {
@@ -45,7 +50,4 @@ while ($true) {
 }
 
 Write-Host ""
-Write-Host "Exiting after failure detection." -ForegroundColor Cyan
-
-# Clean up environment variable
-Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
\ No newline at end of file
+Write-Host "Exiting after failure detection." -ForegroundColor Cyan
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-simple.ps1 b/scripts/windows-debug/test-stdio-simple.ps1
index d249703c42..3cf877ca05 100644
--- a/scripts/windows-debug/test-stdio-simple.ps1
+++ b/scripts/windows-debug/test-stdio-simple.ps1
@@ -1,54 +1,40 @@
 #!/usr/bin/env pwsh
 # Simple script to run the test without xdist
 # Usage: .\test-stdio-simple.ps1
+#
+# Prerequisites: Run . .\setup-environment.ps1 first to ensure tee is available
 
 Write-Host "Running test_stdio_context_manager_exiting with xdist disabled..." -ForegroundColor Cyan
 Write-Host ""
 
-# Method 1: Using environment variable (recommended in CLAUDE.md)
-Write-Host "Method 1: Using PYTEST_DISABLE_PLUGIN_AUTOLOAD environment variable" -ForegroundColor Yellow
-$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
-uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs
-$exitCode1 = $LASTEXITCODE
-Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
-
-if ($exitCode1 -eq 0) {
-    Write-Host "Method 1: PASSED" -ForegroundColor Green
-} else {
-    Write-Host "Method 1: FAILED with exit code $exitCode1" -ForegroundColor Red
+# Check if tee is available
+$teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+if (-not $teeCheck -or $teeCheck -eq "None") {
+    Write-Host "ERROR: tee command not found!" -ForegroundColor Red
+    Write-Host "Please run: . .\setup-environment.ps1" -ForegroundColor Yellow
+    Write-Host "(Note the dot at the beginning to source the script)" -ForegroundColor Yellow
+    exit 1
 }
 
+Write-Host "tee found at: $teeCheck" -ForegroundColor Green
 Write-Host ""
 
-# Method 2: Using -p no:xdist to disable the plugin
-Write-Host "Method 2: Using -p no:xdist flag" -ForegroundColor Yellow
-uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -p no:xdist
-$exitCode2 = $LASTEXITCODE
-
-if ($exitCode2 -eq 0) {
-    Write-Host "Method 2: PASSED" -ForegroundColor Green
-} else {
-    Write-Host "Method 2: FAILED with exit code $exitCode2" -ForegroundColor Red
-}
-
-Write-Host ""
-
-# Method 3: Override addopts from pyproject.toml
-Write-Host "Method 3: Overriding pytest addopts" -ForegroundColor Yellow
+# Run the test with the working method
+Write-Host "Running test with -o addopts='' to override xdist..." -ForegroundColor Yellow
 uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -xvs -o addopts=""
-$exitCode3 = $LASTEXITCODE
-
-if ($exitCode3 -eq 0) {
-    Write-Host "Method 3: PASSED" -ForegroundColor Green
-} else {
-    Write-Host "Method 3: FAILED with exit code $exitCode3" -ForegroundColor Red
-}
+$exitCode = $LASTEXITCODE
 
 Write-Host ""
-Write-Host "========== SUMMARY ==========" -ForegroundColor Cyan
-if ($exitCode1 -eq 0 -or $exitCode2 -eq 0 -or $exitCode3 -eq 0) {
-    Write-Host "At least one method succeeded!" -ForegroundColor Green
-    Write-Host "Use the successful method in your testing."
+if ($exitCode -eq 0) {
+    Write-Host "Test PASSED!" -ForegroundColor Green
+    Write-Host ""
+    Write-Host "You can now use the other scripts to test for flakiness:" -ForegroundColor Cyan
+    Write-Host "  .\test-stdio-flakiness-200-runs.ps1" 
+    Write-Host "  .\test-stdio-flakiness-until-failure.ps1"
+    Write-Host "  .\test-stdio-verbose-debug.ps1"
 } else {
-    Write-Host "All methods failed. The test may have a different issue." -ForegroundColor Red
+    Write-Host "Test FAILED with exit code $exitCode" -ForegroundColor Red
+    Write-Host ""
+    Write-Host "Try running with verbose debug:" -ForegroundColor Yellow
+    Write-Host "  .\test-stdio-verbose-debug.ps1"
 }
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-verbose-debug.ps1 b/scripts/windows-debug/test-stdio-verbose-debug.ps1
index 9696af81eb..593c216cf6 100644
--- a/scripts/windows-debug/test-stdio-verbose-debug.ps1
+++ b/scripts/windows-debug/test-stdio-verbose-debug.ps1
@@ -1,30 +1,37 @@
 #!/usr/bin/env pwsh
 # Script to run test_stdio_context_manager_exiting with maximum debugging output
 # Usage: .\test-stdio-verbose-debug.ps1
+#
+# Prerequisites: Run . .\setup-environment.ps1 first to ensure tee is available
 
 Write-Host "Running test_stdio_context_manager_exiting with verbose debug output..." -ForegroundColor Cyan
 Write-Host ""
 
+# Check if tee is available
+$teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+if (-not $teeCheck -or $teeCheck -eq "None") {
+    Write-Host "ERROR: tee command not found!" -ForegroundColor Red
+    Write-Host "Please run: . .\setup-environment.ps1" -ForegroundColor Yellow
+    Write-Host "(Note the dot at the beginning to source the script)" -ForegroundColor Yellow
+    exit 1
+}
+
 # Set environment variables for debugging
 $env:PYTHONFAULTHANDLER = "1"
 $env:PYTEST_CURRENT_TEST = "1"
-$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
 
 Write-Host "Environment variables set:" -ForegroundColor Yellow
 Write-Host "  PYTHONFAULTHANDLER = 1 (enables Python fault handler)"
-Write-Host "  PYTEST_DISABLE_PLUGIN_AUTOLOAD = '' (disables pytest plugin autoload)"
 Write-Host ""
 
 Write-Host "Running test with maximum verbosity..." -ForegroundColor Cyan
 Write-Host ""
 
 # Run the test with all debugging options
-$env:PYTEST_DISABLE_PLUGIN_AUTOLOAD = ""
 uv run --frozen pytest `
     tests/client/test_stdio.py::test_stdio_context_manager_exiting `
     -xvs `
-    --no-cov `
-    -p no:xdist `
+    -o addopts="" `
     --log-cli-level=DEBUG `
     --log-cli-format="%(asctime)s [%(levelname)s] %(name)s: %(message)s" `
     --capture=no `
@@ -42,5 +49,4 @@ if ($exitCode -eq 0) {
 
 # Clean up environment variables
 Remove-Item Env:PYTHONFAULTHANDLER -ErrorAction SilentlyContinue
-Remove-Item Env:PYTEST_CURRENT_TEST -ErrorAction SilentlyContinue
-Remove-Item Env:PYTEST_DISABLE_PLUGIN_AUTOLOAD -ErrorAction SilentlyContinue
\ No newline at end of file
+Remove-Item Env:PYTEST_CURRENT_TEST -ErrorAction SilentlyContinue
\ No newline at end of file

From 4eb6657f96ade1ad59fc8111314f158316ed22b1 Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 16:32:45 +0100
Subject: [PATCH 5/8] Add parallel and stress test scripts for Windows stdio
 flakiness

Based on deep analysis, the flakiness likely occurs due to:
1. Job Object handle race conditions when tests run in parallel
2. Windows handle inheritance between test processes
3. Timing sensitivity in the minimal test that just opens/closes immediately
4. Python 3.11/3.12 specific subprocess handling changes

These scripts help reproduce the CI environment conditions:
- test-stdio-parallel-flakiness.ps1: Runs with xdist parallel workers
- test-stdio-stress-race.ps1: Rapidly creates processes to expose races
---
 .../test-stdio-parallel-flakiness.ps1         |  94 +++++++++++++
 .../windows-debug/test-stdio-stress-race.ps1  | 125 ++++++++++++++++++
 2 files changed, 219 insertions(+)
 create mode 100644 scripts/windows-debug/test-stdio-parallel-flakiness.ps1
 create mode 100644 scripts/windows-debug/test-stdio-stress-race.ps1

diff --git a/scripts/windows-debug/test-stdio-parallel-flakiness.ps1 b/scripts/windows-debug/test-stdio-parallel-flakiness.ps1
new file mode 100644
index 0000000000..af32801754
--- /dev/null
+++ b/scripts/windows-debug/test-stdio-parallel-flakiness.ps1
@@ -0,0 +1,94 @@
+#!/usr/bin/env pwsh
+# Script to test for flakiness when running tests in parallel (like CI does)
+# This simulates the xdist environment where the issue occurs
+# Usage: .\test-stdio-parallel-flakiness.ps1
+#
+# Prerequisites: Run . .\setup-environment.ps1 first to ensure tee is available
+
+Write-Host "Testing stdio with parallel execution to simulate CI environment..." -ForegroundColor Cyan
+Write-Host ""
+
+# Check if tee is available
+$teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+if (-not $teeCheck -or $teeCheck -eq "None") {
+    Write-Host "ERROR: tee command not found!" -ForegroundColor Red
+    Write-Host "Please run: . .\setup-environment.ps1" -ForegroundColor Yellow
+    Write-Host "(Note the dot at the beginning to source the script)" -ForegroundColor Yellow
+    exit 1
+}
+
+Write-Host "Running tests with different parallel configurations..." -ForegroundColor Yellow
+Write-Host ""
+
+# Test 1: Run with 4 workers (default CI behavior)
+Write-Host "Test 1: Running with 4 parallel workers (CI default)..." -ForegroundColor Cyan
+$failures1 = 0
+for ($i = 1; $i -le 20; $i++) {
+    Write-Host "  Run $i..." -NoNewline
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -v -n 4 2>&1
+    if ($LASTEXITCODE -ne 0) {
+        $failures1++
+        Write-Host " FAILED" -ForegroundColor Red
+    } else {
+        Write-Host " PASSED" -ForegroundColor Green
+    }
+}
+Write-Host "  Result: $failures1 failures out of 20 runs" -ForegroundColor $(if ($failures1 -eq 0) { "Green" } else { "Red" })
+Write-Host ""
+
+# Test 2: Run with 2 workers
+Write-Host "Test 2: Running with 2 parallel workers..." -ForegroundColor Cyan
+$failures2 = 0
+for ($i = 1; $i -le 20; $i++) {
+    Write-Host "  Run $i..." -NoNewline
+    $output = uv run --frozen pytest tests/client/test_stdio.py::test_stdio_context_manager_exiting -v -n 2 2>&1
+    if ($LASTEXITCODE -ne 0) {
+        $failures2++
+        Write-Host " FAILED" -ForegroundColor Red
+    } else {
+        Write-Host " PASSED" -ForegroundColor Green
+    }
+}
+Write-Host "  Result: $failures2 failures out of 20 runs" -ForegroundColor $(if ($failures2 -eq 0) { "Green" } else { "Red" })
+Write-Host ""
+
+# Test 3: Run all stdio tests in parallel (simulates real CI)
+Write-Host "Test 3: Running ALL stdio tests with 4 workers (full CI simulation)..." -ForegroundColor Cyan
+$failures3 = 0
+for ($i = 1; $i -le 10; $i++) {
+    Write-Host "  Run $i..." -NoNewline
+    $output = uv run --frozen pytest tests/client/test_stdio.py -v -n 4 2>&1
+    if ($LASTEXITCODE -ne 0) {
+        $failures3++
+        Write-Host " FAILED" -ForegroundColor Red
+        # Show which test failed
+        $failedTest = $output | Select-String "FAILED tests/client/test_stdio.py::" | Select-Object -First 1
+        if ($failedTest) {
+            Write-Host "    Failed: $failedTest" -ForegroundColor Red
+        }
+    } else {
+        Write-Host " PASSED" -ForegroundColor Green
+    }
+}
+Write-Host "  Result: $failures3 failures out of 10 runs" -ForegroundColor $(if ($failures3 -eq 0) { "Green" } else { "Red" })
+Write-Host ""
+
+# Summary
+Write-Host "========== SUMMARY ==========" -ForegroundColor Cyan
+Write-Host "4 workers (single test): $failures1/20 failures"
+Write-Host "2 workers (single test): $failures2/20 failures"
+Write-Host "4 workers (all tests):   $failures3/10 failures"
+Write-Host ""
+
+if ($failures1 -gt 0 -or $failures2 -gt 0 -or $failures3 -gt 0) {
+    Write-Host "FLAKINESS DETECTED with parallel execution!" -ForegroundColor Red
+    Write-Host ""
+    Write-Host "This confirms the issue is related to parallel test execution." -ForegroundColor Yellow
+    Write-Host "The race condition likely involves:" -ForegroundColor Yellow
+    Write-Host "  - Windows Job Object handle management" -ForegroundColor Gray
+    Write-Host "  - Process cleanup timing with multiple workers" -ForegroundColor Gray
+    Write-Host "  - Handle inheritance between test processes" -ForegroundColor Gray
+} else {
+    Write-Host "No flakiness detected in this run." -ForegroundColor Green
+    Write-Host "The issue might require specific timing conditions to reproduce." -ForegroundColor Yellow
+}
\ No newline at end of file
diff --git a/scripts/windows-debug/test-stdio-stress-race.ps1 b/scripts/windows-debug/test-stdio-stress-race.ps1
new file mode 100644
index 0000000000..633fa7b202
--- /dev/null
+++ b/scripts/windows-debug/test-stdio-stress-race.ps1
@@ -0,0 +1,125 @@
+#!/usr/bin/env pwsh
+# Script to stress test the specific race condition in stdio cleanup
+# This creates many processes rapidly to expose handle/job object races
+# Usage: .\test-stdio-stress-race.ps1
+#
+# Prerequisites: Run . .\setup-environment.ps1 first to ensure tee is available
+
+Write-Host "Stress testing stdio cleanup race conditions..." -ForegroundColor Cyan
+Write-Host "This test creates many processes rapidly to expose timing issues." -ForegroundColor Yellow
+Write-Host ""
+
+# Check if tee is available
+$teeCheck = python -c "import shutil; print(shutil.which('tee'))"
+if (-not $teeCheck -or $teeCheck -eq "None") {
+    Write-Host "ERROR: tee command not found!" -ForegroundColor Red
+    Write-Host "Please run: . .\setup-environment.ps1" -ForegroundColor Yellow
+    Write-Host "(Note the dot at the beginning to source the script)" -ForegroundColor Yellow
+    exit 1
+}
+
+# Create a Python script that runs the test many times in quick succession
+$stressScript = @'
+import asyncio
+import sys
+import time
+from pathlib import Path
+
+# Add parent directories to path
+sys.path.insert(0, str(Path(__file__).parent.parent.parent))
+
+from mcp.client.stdio import stdio_client, StdioServerParameters
+
+async def rapid_test(test_id: int):
+    """Run a single test iteration"""
+    try:
+        async with stdio_client(StdioServerParameters(command="tee")) as (_, _):
+            pass
+        return True, None
+    except Exception as e:
+        return False, str(e)
+
+async def stress_test(iterations: int, concurrent: int):
+    """Run many tests concurrently"""
+    print(f"Running {iterations} tests with {concurrent} concurrent...")
+    
+    failures = 0
+    errors = []
+    start_time = time.time()
+    
+    # Run in batches
+    for batch in range(0, iterations, concurrent):
+        batch_size = min(concurrent, iterations - batch)
+        tasks = [rapid_test(batch + i) for i in range(batch_size)]
+        results = await asyncio.gather(*tasks)
+        
+        for success, error in results:
+            if not success:
+                failures += 1
+                if error and error not in errors:
+                    errors.append(error)
+        
+        # Progress indicator
+        if (batch + batch_size) % 100 == 0:
+            print(f"  Completed {batch + batch_size}/{iterations} tests...")
+    
+    duration = time.time() - start_time
+    return failures, errors, duration
+
+async def main():
+    # Test different concurrency levels
+    configs = [
+        (100, 1),    # Sequential
+        (100, 2),    # Low concurrency
+        (100, 5),    # Medium concurrency
+        (100, 10),   # High concurrency
+    ]
+    
+    for iterations, concurrent in configs:
+        print(f"\nTest: {iterations} iterations, {concurrent} concurrent")
+        failures, errors, duration = await stress_test(iterations, concurrent)
+        
+        print(f"  Duration: {duration:.2f}s")
+        print(f"  Failures: {failures}/{iterations}")
+        if errors:
+            print(f"  Unique errors: {len(errors)}")
+            for error in errors[:3]:  # Show first 3 errors
+                print(f"    - {error}")
+        
+        if failures > 0:
+            print("  RACE CONDITION DETECTED!" if concurrent > 1 else "  FAILURE DETECTED!")
+
+if __name__ == "__main__":
+    asyncio.run(main())
+'@
+
+# Save the stress test script
+$scriptPath = Join-Path $PSScriptRoot "stress_test.py"
+$stressScript | Out-File -FilePath $scriptPath -Encoding UTF8
+
+Write-Host "Running stress tests..." -ForegroundColor Cyan
+Write-Host ""
+
+# Run the stress test
+uv run python $scriptPath
+
+$exitCode = $LASTEXITCODE
+
+# Clean up
+Remove-Item $scriptPath -ErrorAction SilentlyContinue
+
+Write-Host ""
+Write-Host "========== ANALYSIS ==========" -ForegroundColor Cyan
+
+if ($exitCode -ne 0) {
+    Write-Host "Stress test failed to complete." -ForegroundColor Red
+} else {
+    Write-Host "Stress test completed." -ForegroundColor Green
+    Write-Host ""
+    Write-Host "If failures increased with concurrency, it indicates:" -ForegroundColor Yellow
+    Write-Host "  - Race condition in process cleanup" -ForegroundColor Gray
+    Write-Host "  - Job Object handle conflicts" -ForegroundColor Gray
+    Write-Host "  - Windows handle inheritance issues" -ForegroundColor Gray
+    Write-Host ""
+    Write-Host "This matches the CI flakiness pattern where parallel tests fail." -ForegroundColor Yellow
+}
\ No newline at end of file

From 79e5ce71345b7128aa521aa7eae30cc4fa4ba197 Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 16:37:29 +0100
Subject: [PATCH 6/8] remove readme

---
 scripts/windows-debug/README.md | 105 --------------------------------
 1 file changed, 105 deletions(-)
 delete mode 100644 scripts/windows-debug/README.md

diff --git a/scripts/windows-debug/README.md b/scripts/windows-debug/README.md
deleted file mode 100644
index 9f33eed175..0000000000
--- a/scripts/windows-debug/README.md
+++ /dev/null
@@ -1,105 +0,0 @@
-# Windows Test Debugging Scripts
-
-This folder contains PowerShell scripts to help debug the flaky `test_stdio_context_manager_exiting` test on Windows with Python 3.11/3.12.
-
-## Prerequisites
-
-- Windows PowerShell or PowerShell Core
-- Python 3.11 or 3.12
-- `uv` installed and configured
-- Virtual environment activated
-- Git for Windows installed (provides the `tee` command)
-
-## Quick Start
-
-1. First, set up your environment to make `tee` available:
-   ```powershell
-   . .\setup-environment.ps1
-   ```
-   **Note:** The dot (.) at the beginning is important - it sources the script.
-
-2. Verify the test runs:
-   ```powershell
-   .\test-stdio-simple.ps1
-   ```
-
-3. Run the flakiness tests:
-   ```powershell
-   .\test-stdio-flakiness-200-runs.ps1
-   ```
-
-## Scripts
-
-### 1. `setup-environment.ps1`
-Sets up the environment by adding Git for Windows tools to PATH. **Must be dot-sourced.**
-
-```powershell
-. .\setup-environment.ps1
-```
-
-### 2. `check-tee-command.ps1`
-Checks if the `tee` command is available on your Windows system. The test requires `tee` to run.
-
-```powershell
-.\check-tee-command.ps1
-```
-
-### 3. `test-stdio-simple.ps1`
-Runs the test once to verify it works.
-
-```powershell
-.\test-stdio-simple.ps1
-```
-
-### 4. `test-stdio-flakiness-200-runs.ps1`
-Runs the test 200 times and reports the failure rate.
-
-```powershell
-.\test-stdio-flakiness-200-runs.ps1
-```
-
-### 5. `test-stdio-flakiness-until-failure.ps1`
-Runs the test in a loop until it fails, useful for catching intermittent failures.
-
-```powershell
-.\test-stdio-flakiness-until-failure.ps1
-```
-
-### 6. `test-stdio-verbose-debug.ps1`
-Runs the test once with maximum debugging output enabled.
-
-```powershell
-.\test-stdio-verbose-debug.ps1
-```
-
-## Usage Notes
-
-1. Make sure your virtual environment is activated before running these scripts
-2. Always run `setup-environment.ps1` first in each new PowerShell session
-3. Run scripts from the `scripts\windows-debug` directory
-4. If scripts fail with execution policy errors, run:
-   ```powershell
-   Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
-   ```
-
-## Interpreting Results
-
-- If `tee` is not available, the test will be skipped
-- Flaky failures typically show up as timeout errors or process cleanup issues
-- Look for patterns in failure output, especially around process termination timing
-
-## Troubleshooting
-
-### "tee command not found"
-1. Install Git for Windows from https://gitforwindows.org/
-2. Run `. .\setup-environment.ps1` to add Git tools to PATH
-3. Verify with `python -c "import shutil; print(shutil.which('tee'))"`
-
-### "no tests ran" with xdist
-The scripts now use `-o addopts=""` to override the pytest configuration that enables xdist by default.
-
-### Making PATH changes permanent
-Add this line to your PowerShell profile:
-```powershell
-$env:PATH = "C:\Program Files\Git\usr\bin;$env:PATH"
-```
\ No newline at end of file

From 4cab85c3ca09696a893fe949f2400aac7f153f1b Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 16:39:38 +0100
Subject: [PATCH 7/8] Add environment diagnostic script for Windows CI
 differences

This script collects detailed information about:
- Windows version and build
- Python version and subprocess configuration
- Job Objects support
- Security software
- Process creation timing
- Handle inheritance settings

This will help identify differences between local dev environments
(where the test passes) and CI environments (where it flakes).
---
 .../windows-debug/diagnose-environment.ps1    | 152 ++++++++++++++++++
 scripts/windows-debug/test.txt                |   0
 2 files changed, 152 insertions(+)
 create mode 100644 scripts/windows-debug/diagnose-environment.ps1
 create mode 100644 scripts/windows-debug/test.txt

diff --git a/scripts/windows-debug/diagnose-environment.ps1 b/scripts/windows-debug/diagnose-environment.ps1
new file mode 100644
index 0000000000..5d49480b23
--- /dev/null
+++ b/scripts/windows-debug/diagnose-environment.ps1
@@ -0,0 +1,152 @@
+#!/usr/bin/env pwsh
+# Script to diagnose environment differences that might cause CI flakiness
+# Usage: .\diagnose-environment.ps1
+
+Write-Host "Diagnosing Windows environment for stdio test issues..." -ForegroundColor Cyan
+Write-Host ""
+
+# System Information
+Write-Host "=== SYSTEM INFORMATION ===" -ForegroundColor Yellow
+Write-Host "Windows Version:"
+(Get-CimInstance Win32_OperatingSystem).Version
+Write-Host "Windows Build:"
+(Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion").DisplayVersion
+Write-Host ""
+
+# Python Information
+Write-Host "=== PYTHON INFORMATION ===" -ForegroundColor Yellow
+Write-Host "Python Version:"
+python --version
+Write-Host ""
+Write-Host "Python Build Info:"
+python -c "import sys; print(f'Version: {sys.version}')"
+python -c "import sys; print(f'Platform: {sys.platform}')"
+python -c "import sys; print(f'Windows Version: {sys.getwindowsversion()}')"
+Write-Host ""
+
+# Check subprocess configuration
+Write-Host "=== SUBPROCESS CONFIGURATION ===" -ForegroundColor Yellow
+python -c @"
+import subprocess
+import sys
+print(f'CREATE_NO_WINDOW available: {hasattr(subprocess, "CREATE_NO_WINDOW")}')
+print(f'CREATE_NEW_PROCESS_GROUP available: {hasattr(subprocess, "CREATE_NEW_PROCESS_GROUP")}')
+print(f'Windows subprocess startup info: {hasattr(subprocess, "STARTUPINFO")}')
+
+# Check handle inheritance defaults
+import os
+print(f'\nHandle inheritance (os.O_NOINHERIT): {hasattr(os, "O_NOINHERIT")}')
+
+# Check asyncio event loop
+import asyncio
+try:
+    loop = asyncio.get_event_loop_policy()
+    print(f'Event loop policy: {type(loop).__name__}')
+except:
+    print('Event loop policy: Unable to determine')
+"@
+Write-Host ""
+
+# Check for Job Objects support
+Write-Host "=== JOB OBJECTS SUPPORT ===" -ForegroundColor Yellow
+python -c @"
+try:
+    import win32job
+    import win32api
+    print('pywin32 available: Yes')
+    print(f'win32job version: {win32job.__file__}')
+    
+    # Try to create a job object
+    try:
+        job = win32job.CreateJobObject(None, '')
+        win32api.CloseHandle(job)
+        print('Job Object creation: Success')
+    except Exception as e:
+        print(f'Job Object creation: Failed - {e}')
+except ImportError:
+    print('pywin32 available: No (Job Objects not available)')
+"@
+Write-Host ""
+
+# Check process limits
+Write-Host "=== PROCESS LIMITS ===" -ForegroundColor Yellow
+python -c @"
+import os
+import psutil
+proc = psutil.Process(os.getpid())
+print(f'Open handles: {proc.num_handles()}')
+print(f'Open files: {len(proc.open_files())}')
+
+# Check system-wide limits
+print(f'Total processes: {len(psutil.pids())}')
+"@
+Write-Host ""
+
+# Check security software
+Write-Host "=== SECURITY SOFTWARE ===" -ForegroundColor Yellow
+Get-CimInstance -Namespace "root\SecurityCenter2" -ClassName AntiVirusProduct -ErrorAction SilentlyContinue | 
+    Select-Object displayName, productState | Format-Table
+Write-Host ""
+
+# Test rapid process creation
+Write-Host "=== RAPID PROCESS CREATION TEST ===" -ForegroundColor Yellow
+Write-Host "Testing rapid tee process creation/destruction..."
+$testScript = @'
+import time
+import subprocess
+import sys
+
+failures = 0
+times = []
+
+for i in range(20):
+    start = time.time()
+    try:
+        # Create process with same flags as stdio client
+        proc = subprocess.Popen(
+            ['tee'],
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            creationflags=getattr(subprocess, 'CREATE_NO_WINDOW', 0)
+        )
+        proc.stdin.close()
+        proc.wait(timeout=0.5)
+        elapsed = time.time() - start
+        times.append(elapsed)
+    except Exception as e:
+        failures += 1
+        print(f"  Iteration {i+1}: FAILED - {e}")
+    
+    if (i+1) % 5 == 0:
+        avg_time = sum(times) / len(times) if times else 0
+        print(f"  Completed {i+1}/20 (avg: {avg_time*1000:.1f}ms)")
+
+print(f"\nFailures: {failures}/20")
+if times:
+    print(f"Average time: {sum(times)/len(times)*1000:.1f}ms")
+    print(f"Max time: {max(times)*1000:.1f}ms")
+'@
+
+python -c $testScript
+Write-Host ""
+
+# Environment variables that might affect subprocess
+Write-Host "=== RELEVANT ENVIRONMENT VARIABLES ===" -ForegroundColor Yellow
+@("COMSPEC", "PATH", "PYTHONPATH", "PYTHONASYNCIODEBUG") | ForEach-Object {
+    $value = [Environment]::GetEnvironmentVariable($_)
+    if ($value) {
+        Write-Host "$_`:"
+        Write-Host "  $value" -ForegroundColor Gray
+    }
+}
+Write-Host ""
+
+Write-Host "=== DIAGNOSIS COMPLETE ===" -ForegroundColor Cyan
+Write-Host ""
+Write-Host "Share this output when reporting the flakiness issue." -ForegroundColor Yellow
+Write-Host "Key differences to look for between local and CI:" -ForegroundColor Yellow
+Write-Host "  - Windows version/build" -ForegroundColor Gray
+Write-Host "  - Python build details" -ForegroundColor Gray
+Write-Host "  - Security software presence" -ForegroundColor Gray
+Write-Host "  - Process creation timing" -ForegroundColor Gray
\ No newline at end of file
diff --git a/scripts/windows-debug/test.txt b/scripts/windows-debug/test.txt
new file mode 100644
index 0000000000..e69de29bb2

From 6be585d008e232f62cdf7c19a881cf605a385d6a Mon Sep 17 00:00:00 2001
From: Felix Weinberger <fweinberger@anthropic.com>
Date: Wed, 16 Jul 2025 17:14:40 +0100
Subject: [PATCH 8/8] trigger ci

---
 test.txt | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 test.txt

diff --git a/test.txt b/test.txt
new file mode 100644
index 0000000000..5ca2944976
--- /dev/null
+++ b/test.txt
@@ -0,0 +1,6 @@
+hello
+test
+test
+test
+test
+test