claude-mem/docs/reports/2026-01-04--issue-517-windows-powershell-analysis.md

Issue #517 Analysis: Windows PowerShell Escaping in cleanupOrphanedProcesses()

Date: 2026-01-04 Version Analyzed: 8.5.7 Status: NOT FIXED - Issue still present

Summary

The reported issue involves PowerShell's $_ variable being interpreted by Bash before PowerShell receives it when running in Git Bash or WSL environments on Windows. This causes cleanupOrphanedProcesses() to fail during worker initialization.

Current State

The cleanupOrphanedProcesses() function is located in:

• File: /Users/alexnewman/Scripts/claude-mem/src/services/infrastructure/ProcessManager.ts
• Lines: 164-251

Problematic Code (Lines 170-172)

if (isWindows) {
  // Windows: Use PowerShell Get-CimInstance to find chroma-mcp processes
  const cmd = `powershell -Command "Get-CimInstance Win32_Process | Where-Object { $_.Name -like '*python*' -and $_.CommandLine -like '*chroma-mcp*' } | Select-Object -ExpandProperty ProcessId"`;
  const { stdout } = await execAsync(cmd, { timeout: 60000 });

The $_.Name and $_.CommandLine contain $_ which is a special variable in both PowerShell and Bash. When this command string is executed via Node.js child_process.exec() in a Git Bash or WSL environment, Bash may interpret $_ as its own special variable (the last argument of the previous command) before passing it to PowerShell.

Additional Occurrence (Lines 91-92)

A similar issue exists in getChildProcesses():

const cmd = `powershell -Command "Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq ${parentPid} } | Select-Object -ExpandProperty ProcessId"`;

Error Handling Analysis

Both functions have try-catch blocks with non-blocking error handling:

• Line 208-212: cleanupOrphanedProcesses() catches errors and logs a warning, then returns
• Line 98-102: getChildProcesses() catches errors and logs a warning, returning empty array

While this prevents worker initialization from crashing, it means orphaned process cleanup silently fails on affected Windows environments.

Recommended Fix

Replace PowerShell commands with WMIC (Windows Management Instrumentation Command-line), which does not use $_ syntax:

For cleanupOrphanedProcesses() (Line 171):

Current:

const cmd = `powershell -Command "Get-CimInstance Win32_Process | Where-Object { $_.Name -like '*python*' -and $_.CommandLine -like '*chroma-mcp*' } | Select-Object -ExpandProperty ProcessId"`;

Recommended:

const cmd = `wmic process where "name like '%python%' and commandline like '%chroma-mcp%'" get processid /format:list`;

For getChildProcesses() (Line 91):

Current:

const cmd = `powershell -Command "Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq ${parentPid} } | Select-Object -ExpandProperty ProcessId"`;

Recommended:

const cmd = `wmic process where "parentprocessid=${parentPid}" get processid /format:list`;

Implementation Notes

1. WMIC output format differs from PowerShell - parse ProcessId=12345 format
2. WMIC is deprecated in newer Windows versions but still widely available
3. Alternative: Use PowerShell with proper escaping ($$_ or \$_ depending on context)
4. Consider using powershell -NoProfile -NonInteractive flags for faster execution

Impact Assessment

• Severity: Medium - orphaned process cleanup fails silently
• Scope: Windows users running in Git Bash, WSL, or mixed shell environments
• Workaround: None currently - users must manually kill orphaned chroma-mcp processes

Files to Modify

1. /src/services/infrastructure/ProcessManager.ts (lines 91-92, 171-172)