Asp.Net Core: Debug -Attach to process is not working

Question

The way we are used to debug a running "IISExpress" process in .Net Framework is by attaching a process by the name "iisexpress.exe" in Visual Studio. But attaching the iisexpress process is not working in .Net core. It shows the message - "The breakpoint will not currently be hit. No symbols have been loaded for this document."

related: https://stackoverflow.com/questions/50806765/to-which-process-should-i-attach-visual-studio-debugger-to-debug-a-kestrel-appli — Ruben Bartelink, Dec 05 '18 at 14:31

tech-y · Accepted Answer · 2021-03-17T06:43:15.087

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To debug a running iisexpress instance in .Net core, you will have to attach "dotnet.exe" process in Visual Studio.
*Update - 1: If dotnet.exe does not work for you, check "{projectName}.exe" as well. *Update -2: Attaching "iisexpress.exe" works with .net 5

edited Mar 17 '21 at 06:43

answered Mar 15 '18 at 11:02

tech-y

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Thanks for sharing your solution here, you could mark it as the answer later. Have a nice day. – Fletcher Mar 16 '18 at 05:42
Thank you very much – Osama khodrog Nov 18 '20 at 10:38
I think this is not working for .Net Core 3.0+ projects. Attaching to "dotnet.exe" process(es) gives me a warning message on the breakpoint. Attaching to the .exe does the job. – mihkov Jan 19 '21 at 17:56

Daniel Archer · Answer 2 · 2019-11-04T07:54:23.330

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In Visual Studio 2019 using "dotnet watch run" I could no longer attach to the "dotnet.exe" process, I would get the Symbols could not be loaded error, took me a while to figure out but instead I attached to [project name].exe which is in the list of running processes and I could successfully attach the debugger to a process with symbols loaded and debug.

edited Nov 04 '19 at 07:54

answered Nov 04 '19 at 05:46

Daniel Archer

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score 1 · Answer 3 · answered Mar 06 '19 at 13:09

In my case, using Asp.Net Core 2.2 with InProcess Hosting Model, the accepted answer doesn't work. But, I should choose from the menu Debug > Attach to process, then select the "Show processes from all users" checkbox (below the list of process) and select "iisexpress.exe". It works properly and hit the break points.

score 0 · Answer 4 · answered May 12 '19 at 06:27

Visual studio does not loads all dlls (don't know why). Try this:

1) First attach with w3wp.exe (for InProcess Hosting) or dotnet.exe (for OutOfProcess Hosting)

2) Load Symbols manually:

Go to Debug > Windows > Modules (or try shortcut Ctrl + Alt + U)

Search and select dll (and dependent dll's) which you want to debug and right click > Load Symbols.

Asp.Net Core: Debug -Attach to process is not working

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