dotnet-windbg-debugging

Windows user-mode debugging using WinDbg MCP tools. Applicable to any Windows application -- native, managed (.NET/CLR), or mixed-mode. Guides investigation of crash dumps, application hangs, high CPU, and memory pressure through structured command packs and report templates.

Platform: Windows only.

Scope

• Crash dump analysis (.dmp files) for any Windows process (native, .NET, or mixed-mode)
• Live process attach via cdb debug server
• Hang and deadlock diagnosis (thread analysis, lock detection)
• High CPU triage (runaway thread identification)
• Memory pressure and leak investigation via native heap analysis
• Kernel dump triage (BSOD / bugcheck analysis)
• COM/RPC wait chain and UI message pump analysis
• Structured diagnostic reports with stack evidence

Out of scope

• .NET SDK diagnostic tools (dotnet-counters, dotnet-trace, dotnet-dump) -- see [skill:dotnet-profiling]
• GC tuning and managed memory optimization -- see [skill:dotnet-gc-memory]
• Performance benchmarking and regression detection -- see [skill:dotnet-benchmarkdotnet]
• Application performance architecture patterns -- see [skill:dotnet-performance-patterns]

MCP Tool Contract

Use these

mcp-windbg

operations:

1. mcp_mcp-windbg_open_windbg_remote

   -- attach to a live debug server

2. mcp_mcp-windbg_open_windbg_dump

   -- open a saved dump file

3. mcp_mcp-windbg_run_windbg_cmd

   -- execute debugger commands

4. mcp_mcp-windbg_close_windbg_remote

   -- detach from live session

5. mcp_mcp-windbg_close_windbg_dump

   -- close dump session

Quick Start

1. Configure and access MCP: see

   reference/access-mcp.md

2. Choose workflow:
   • Live attach: see

     reference/live-attach.md

   • Dump analysis: see

     reference/dump-workflow.md

3. Choose a task reference: see

   reference/scenario-command-packs.md

4. Use support references as needed:
   • Sanity check:

     reference/sanity-check.md

   • Symbols:

     reference/symbols.md

   • Common patterns:

     reference/common-patterns.md

   • Capture playbooks:

     reference/capture-playbooks.md

5. Return results using

   reference/report-template.md

6. Close the debug session.

Completion Criteria

• Correct mode selected (live or dump)
• Task reference executed for the symptom
• Findings reference concrete stacks/threads/modules
• Session closed cleanly

Guardrails

• Do not claim certainty without callee-side evidence
• Do not call it a deadlock unless lock/wait evidence supports it
• Preserve user privacy: do not include secrets from environment blocks in reports

Cross-references: [skill:dotnet-profiling] for .NET SDK diagnostic tools, [skill:dotnet-gc-memory] for managed GC and memory tuning.

References

• WinDbg MCP -- MCP server for WinDbg integration
• WinDbg Documentation -- Microsoft debugger documentation