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DoubleWritesAnalyzer produces false positives

See original GitHub issue

Scenario

C:\foo\FooApp\FooApp.sln includes the following projects.
- C:\foo\FooApp\FooApp\FooApp.csproj
- C:\foo\FooApp\FooApp.Tasks\FooApp.Tasks.csproj
The solution configuration specifies that both projects should build.
C:\foo\FooApp\FooApp\FooApp.csproj includes the following ProjectReference.

    <ProjectReference Include="..\FooApp.Tasks\FooApp.Tasks.csproj">
      <Project>{34c3ce97-aed1-4a7c-a105-9a41e6de5af5}</Project>
      <Name>FooApp.Tasks</Name>
    </ProjectReference>

The solution is built with a command line like the following. "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\MSBuild.exe" "C:\foo\FooApp\FooApp.sln" /t:build /v:diag /nologo /noconlog /logger:StructuredLogger,"C:\Users\FooUser\AppData\Local\MSBuildStructuredLogViewer\app-1.2.12\StructuredLogger.dll";"C:\Users\FooUser\AppData\Local\Temp\1\MSBuildStructuredLog-16128.buildlog"

Problem

The DoubleWrites report includes the following entry:

bin\Debug\netstandard2.0\FooApp.Tasks.dll

obj\Debug\netstandard2.0\FooApp.Tasks.dll

C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll

However, the reported destination file bin\Debug\netstandard2.0\FooApp.Tasks.dll is really 2 files:

C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll
C:\foo\FooApp\FooApp\bin\Debug\netstandard2.0\FooApp.Tasks.dll

The DoubleWrites entry is therefore a false positive.

Log excerpts

Context of Excerpt 1

Project FooApp.sln (build target(s))
-> FooApp.csproj
--> Project FooApp.csproj (default targets)
---> Project FooApp.csproj (Build target(s))
----> Project FooApp.Tasks.csproj (default targets)
-----> Target Build
------> Target CoreBuild
-------> Target PrepareForRun
--------> Target CopyFilesToOutputDirectory
---------> Task Copy:

Excerpt 1

Copy
    Assembly = Microsoft.Build.Tasks.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
    Parameters
        SourceFiles = obj\Debug\netstandard2.0\FooApp.Tasks.dll
        DestinationFolder = bin\Debug\netstandard2.0\
        SkipUnchangedFiles = True
        OverwriteReadOnlyFiles = False
        UseHardlinksIfPossible = False
        UseSymboliclinksIfPossible = False
     Copying file from "obj\Debug\netstandard2.0\FooApp.Tasks.dll" to "bin\Debug\netstandard2.0\FooApp.Tasks.dll".

Context of Excerpt 2

Project FooApp.sln (build target(s))
-> FooApp.csproj
--> Project FooApp.csproj (default targets)
---> Project FooApp.csproj (Build target(s))
----> Target Build
-----> Target CoreBuild
------> Target PrepareForRun
-------> Target CopyFilesToOutputDirectory
--------> Target _CopyFilesMarkedCopyLocal
---------> Task Copy:

Excerpt 2

Copy
    Assembly = Microsoft.Build.Tasks.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
    Parameters
        SourceFiles
            C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll
                BuildReference = true
                Configuration = Debug
                CopyLocal = true
                CopyUpToDateMarker = C:\foo\FooApp\FooApp.Tasks\obj\Debug\netstandard2.0\FooApp.Tasks.csproj.CopyComplete
                FullConfiguration = Debug|AnyCPU
                FusionName = FooApp.Tasks, Version=1.3.0.0, Culture=neutral, PublicKeyToken=null
                HasSingleTargetFramework = false
                ImageRuntime = v4.0.30319
                IsRidAgnostic = true
                MSBuildSourceProjectFile = C:\foo\FooApp\FooApp.Tasks\FooApp.Tasks.csproj
                MSBuildSourceTargetName = GetTargetFrameworks
                Name = FooApp.Tasks
                NearestTargetFramework = netstandard2.0
                OriginalItemSpec = C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll
                OriginalProjectReferenceItemSpec = ..\FooApp.Tasks\FooApp.Tasks.csproj
                OutputItemType = 
                Platform = AnyCPU
                Project = {34c3ce97-aed1-4a7c-a105-9a41e6de5af5}
                ProjectReferenceOriginalItemSpec = ..\FooApp.Tasks\FooApp.Tasks.csproj
                ReferenceOutputAssembly = true
                ReferenceSourceTarget = ProjectReference
                ResolvedFrom = C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll
                SetConfiguration = Configuration=Debug
                SetPlatform = Platform=AnyCPU
                SetTargetFramework = TargetFramework=netstandard2.0
                TargetFrameworkIdentifier = .NETStandard
                TargetFrameworks = netstandard2.0;net40
                TargetFrameworkVersion = 2.0
                TargetPlatformIdentifier = Windows
                TargetPlatformMoniker = Windows,Version=7.0
                Targets = 
                UndefineProperties = ;RuntimeIdentifier
                Version = 
        DestinationFiles
            bin\Debug\netstandard2.0\FooApp.Tasks.dll
                BuildReference = true
                Configuration = Debug
                CopyLocal = true
                CopyUpToDateMarker = C:\foo\FooApp\FooApp.Tasks\obj\Debug\netstandard2.0\FooApp.Tasks.csproj.CopyComplete
                FullConfiguration = Debug|AnyCPU
                FusionName = FooApp.Tasks, Version=1.3.0.0, Culture=neutral, PublicKeyToken=null
                HasSingleTargetFramework = false
                ImageRuntime = v4.0.30319
                IsRidAgnostic = true
                MSBuildSourceProjectFile = C:\foo\FooApp\FooApp.Tasks\FooApp.Tasks.csproj
                MSBuildSourceTargetName = GetTargetFrameworks
                Name = FooApp.Tasks
                NearestTargetFramework = netstandard2.0
                OriginalItemSpec = C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll
                OriginalProjectReferenceItemSpec = ..\FooApp.Tasks\FooApp.Tasks.csproj
                OutputItemType = 
                Platform = AnyCPU
                Project = {34c3ce97-aed1-4a7c-a105-9a41e6de5af5}
                ProjectReferenceOriginalItemSpec = ..\FooApp.Tasks\FooApp.Tasks.csproj
                ReferenceOutputAssembly = true
                ReferenceSourceTarget = ProjectReference
                ResolvedFrom = C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll
                SetConfiguration = Configuration=Debug
                SetPlatform = Platform=AnyCPU
                SetTargetFramework = TargetFramework=netstandard2.0
                TargetFrameworkIdentifier = .NETStandard
                TargetFrameworks = netstandard2.0;net40
                TargetFrameworkVersion = 2.0
                TargetPlatformIdentifier = Windows
                TargetPlatformMoniker = Windows,Version=7.0
                Targets = 
                UndefineProperties = ;RuntimeIdentifier
                Version = 
        SkipUnchangedFiles = True
        OverwriteReadOnlyFiles = False
        UseHardlinksIfPossible = False
        UseSymboliclinksIfPossible = False
     Copying file from "C:\foo\FooApp\FooApp.Tasks\bin\Debug\netstandard2.0\FooApp.Tasks.dll" to "bin\Debug\netstandard2.0\FooApp.Tasks.dll".

Issue Analytics

State:
Created 5 years ago
Comments:5 (5 by maintainers)

Top GitHub Comments

2reactions

KirillOsenkovcommented, Jul 11, 2018

Thanks for reporting. This is because the Copy task uses relative paths. We need to get MSBuild to switch to logging absolute paths there, then this won’t be an issue.

0reactions

KirillOsenkovcommented, May 29, 2019

I can confirm that the double-writes are gone and the Copy task now logs full paths: