Remove a DLL from the bin folder in the Build Pipeline - msbuild

Question

I have the following build script which is not working with Azure Devops Build Pipelines. After Building the solution, I am trying to delete a specific DLL from the bin folder which works locally but not in the build pipeline.
<PropertyGroup>
<PostBuildEvent>
cd $(TargetDir)
del Sample.dll
</PostBuildEvent>
</PropertyGroup>
Build Solution Definition
steps:
- task: VSBuild#1 displayName: 'Build solution' inputs:
solution: '$(Parameters.solution)'
vsVersion: 15.0
msbuildArgs: '/p:DeployOnBuild=true /p:WebPublishMethod=Package /p:PackageAsSingleFile=false /p:SkipInvalidConfigurations=true /p:PackageLocation="$(Build.ArtifactStagingDirectory)\\" /p:Configuration=Release'
platform: '$(BuildPlatform)'
configuration: '$(BuildConfiguration)'
maximumCpuCount: true
Delete
steps:
- task: DeleteFiles#1
displayName: 'Delete files from $(Build.ArtifactStagingDirectory)'
inputs:
SourceFolder: '$(Build.ArtifactStagingDirectory)'
Contents: |
\Sage.Common.LinqBridge*\
\Sage.Common.LinqBridge.dll*\
Publish
steps:
- task: PublishBuildArtifacts#1
displayName: 'Publish Artifact'
inputs:
ArtifactName: '$(Parameters.ArtifactName)'
condition: succeededOrFailed()
Solution:
Thank you #Levi Lu-MSFT in helping me with the solution.
In the delete task, changing the delete pattern worked. For reference,
steps:
- task: DeleteFiles#1
displayName: 'Delete files from $(Build.ArtifactStagingDirectory)'
inputs:
SourceFolder: '$(Build.ArtifactStagingDirectory)'
Contents: '**\Sage.Common.LinqBridge.dll'

Answer 1

Remove a DLL from the bin folder in the Build Pipeline
I have created a sample to test, and it works fine on my side.
To resolve this issue, I would like provide following trouleshootings:
Check the build log, to found out if the PostBuildEvent is executed successfully.
Make sure you have specify the correct MSBuild arguments in the build task, like: /property:Configuration=Release:
If you are using the private agent, make sure you have permission to delete file from the private agent. Or you can test it with hosted agent.
Update:
According to the error log, we could to know you are publishing the project and delete the one .dll file in the post build event.
If you check the log, you will find MSBuild get the files from the folder obj\Release\Package\PackageTmp\bin rather than bin folder. That is the reason why the Sage.Common.LinqBridge.dll still exists after you delete it.
Check the log:
Adding file (d:\a\8\s\xx\xxx\xxx\xxx\obj\Release\Package\PackageTmp\bin\Sage.Common.LinqBridge.dll)
And you could not delete that file in the .zip by the delete task.
To resolve this issue, you could set Copy Local to False for that dll file.
Update2:
After talk with mbharanidharan88, found the reason for this issue is that not use correct syntax in the contents in the delete task.
To delete the file only in the bin folder, we could use the following syntax:
**\bin\Sage.Common.LinqBridge.dll
Hope this helps.