升级VS2017 15.7.1后无法调试U-SQL本地C#代码，本地运行失败

Hey there, sorry to hear you're stuck with this frustrating debugging issue—nothing's more annoying than a vague "run failed" error when your script works fine in regular execution! Let's break down where to find the details and fix this:

Where to Find Detailed Debug Logs #

First, let's track down the actual error details that the generic VS message hides. The local U-SQL runtime keeps detailed logs that don't show up in the Event Viewer or VS output window. Head to this path on your machine:
C:\Users\<YourUsername>\AppData\Local\USQLSDK\Logs
Look for the most recent timestamped log files—these will include full error stacks, assembly load failures, permission issues, or debugger attachment problems that explain why the debug run terminated.

Step-by-Step Troubleshooting Tips #

• Verify Debugger Configuration
  Right-click your U-SQL project → Properties → Debug tab. Double-check:

  • The Debugger Type is set to Managed (CoreCLR) (U-SQL's local runtime uses .NET Core, so this is critical for proper debugging attachment)
  • The Command Arguments correctly point to your .usql script file (no typos or missing file paths)

• Check Assembly Deployment Settings
  For your custom assembly reference in the U-SQL project, right-click the reference → Properties and confirm Copy Local is set to True. When debugging, VS needs to copy your DLL to the local runtime's working directory—if this is missing, the runtime can't load your extractor, leading to a silent failure.

• Test with a Minimal Repro Script
  Create a stripped-down U-SQL script that only calls the most basic functionality of your custom extractor (no complex joins, filters, or extra dependencies). If this minimal script debugs successfully, the problem lies in your original script's logic or conflicting dependencies. If it still fails, the issue is tied to your assembly or the local runtime environment.

• Clear Corrupted Caches
  Stale caches are a common culprit here. Try these steps:

  • Close Visual Studio completely
  • Delete the Component Model Cache: C:\Users\<YourUsername>\AppData\Local\Microsoft\VisualStudio\15.0_<YourVSInstanceID>\ComponentModelCache
  • Wipe the local U-SQL working directory: C:\Users\<YourUsername>\AppData\Local\USQLSDK\LocalRun
  • Restart VS, rebuild your solution, and try debugging again

• Address VS Version Compatibility
  You mentioned auto-updating to VS 15.7.1 caused issues even after trying to stick to 15.6.x. Newer VS versions can sometimes have compatibility bugs with the U-SQL SDK. Try manually installing a version-specific U-SQL SDK that aligns with VS 15.6.x (via official Microsoft download channels) to resolve potential conflicts.

From the error screenshot you shared, it's clear the local debug process is terminating abruptly without surfacing the root cause—digging into the USQLSDK logs should be your first step to uncovering exactly what's going wrong.

内容的提问来源于stack exchange，提问作者Bill Blakey