dotnet/msbuild

MSBuild does not cooperate with Restart Manager on Windows

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#12,776 opened on Nov 17, 2025

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help wantedtriaged

Description

Summary

Lingering MSBuild processes lock .NET assembly files with MSBuild tasks, blocking the possibility of changing them.

Background and Motivation

After dotnet build command completion, there are plenty of running dotnet processes launched with the following command line:

Module:                         dotnet.exe, 64-bit
Full path:                      C:\Program Files\dotnet\dotnet.exe

Command Line:
"C:\Program Files\dotnet\dotnet.exe" "C:\Program Files\dotnet\sdk\10.0.100\MSBuild.dll" /noautoresponse /nologo /nodemode:1 /nodeReuse:true /low:false

Those MSBuild processes are lingering around well after a build is completed.

If the build uses a 3rd party .DLL file with MSBuild tasks, the task file gets locked by one of the running dotnet processes. This creates problem for MSI installers that want to remove/modify that .DLL file.

Proposed Feature

This would not pose a problem if MSBuild could cooperate with Windows restart manager. However, as of MSBuild 18.0 / .NET SDK 10.0.100, MSBuild does not support its semantics. As a result, package installers have no clear way of tearing blocking MSBuild processes down, and this creates a painful experience for the end users if they happen to launch an installer soon enough after the last build.

Alternative Designs

No response

Contributor guide

Tech stack
csharp
Domain
build system
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
5
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
C# knowledgeWindows process managementMSBuild internalsRestart Manager API
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
5
Research direction
The issue requests MSBuild to integrate with Windows Restart Manager to avoid locking files. Investigate MSBuild's current process management in the node reuse implementation (likely in /src/MSBuild/). Review the Restart Manager API documentation. Examine how other build tools handle file locks on Windows. Check for any existing discussions or PRs referenced in comments. Note that the issue mentions /noautoresponse and /nodemode:1 flags; those may be relevant to the lingering process behavior.