[Bug]: Copy.DoCopyWithRetries logs warnings without a diagnostic code

[RobSwDev]

Issue Description

See #9190 CI builds frequently fail with MSB3021: Access to the path xxx.dll is denied

I'm using the secret MSBUILDALWAYSRETRY environmental variable to mitigate lots of Copy conflicts that unexpectedly started occurring last month.

However, when this retry happens, a warning is logged without a diagnostic code.
This means that I cannot exclude this warning in our "strict" build that treats warnings as errors:

msbuild/src/Tasks/Copy.cs

Line 817 in 971bf70

LogDiagnostic("Got {0} copying {1} to {2} and HR is {3}", e.ToString(), sourceFileState.Name, destinationFileState.Name, code);

I'm currently giving these arguments to MSBuild:
/WarnAsError /nowarn:"MSB3270;MSB3026;MSB3021" /maxcpucount:1
I'd like to add "LogDiagnostic" warnings to the /nowarn list, but without a diagnostic code, I cannot see how to do so.

We are building to a single directory, so nuget packages that are referenced by multiple projects tend to get written multiple times. But even building single threaded, I cannot seem to avoid conflicts.

Microsoft.Common.CurrentVersion.targets(5167,5): error : Got System.IO.IOException: The process cannot access the file 'F:\build\bin\AnyCPU\Release\net472\libcef.dll' because it is being used by another process.
Microsoft.Common.CurrentVersion.targets(5167,5): error :    at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
Microsoft.Common.CurrentVersion.targets(5167,5): error :    at System.IO.File.InternalCopy(String sourceFileName, String destFileName, Boolean overwrite, Boolean checkHost)
Microsoft.Common.CurrentVersion.targets(5167,5): error :    at System.IO.File.Copy(String sourceFileName, String destFileName, Boolean overwrite)
Microsoft.Common.CurrentVersion.targets(5167,5): error :    at Microsoft.Build.Tasks.Copy.CopyFileWithLogging(FileState sourceFileState, FileState destinationFileState)
Microsoft.Common.CurrentVersion.targets(5167,5): error :    at Microsoft.Build.Tasks.Copy.DoCopyWithRetries(FileState sourceFileState, FileState destinationFileState, CopyFileWithState copyFile) copying d:\Nuget\packages\cef.redist.x64\103.0.9\CEF\libcef.dll to F:\build\bin\AnyCPU\Release\net472\libcef.dll and HR is -2147024864

Steps to Reproduce

Unable to provide steps to reproduce, as I don't know what changed in our build environment (around the 10th August) that causes so many Copy File conflicts.

Expected Behavior

Ideally, warnings should include a diagnostic code.

Actual Behavior

Warning does not currently include a diagnostic code.

Analysis

No response

Versions & Configurations

No response

[rokonec]

@RobSwDev we will, most probably, make it suppressible.

Meanwhile, would you please share with us build binary log https://aka.ms/binlog ? I can help us to understand root cause of your issues with Copy task.

[RobSwDev]

I have binary logs, though I'm not sure I can share them due to sensitive data they may contain.

I've assumed up to now that the root cause is something to do with platform or environment changes (perhaps AV), and nothing to do with MSBuild. Or is it possible there has been a change in the build tools?

#9169 seems to be related to our issue. And the fact that our copy issues started around the time the 7.0.4 sdk was released was an interesting coincidence.
But according to our build agent logs, our agents didn't actually upgrade until a day or two later, and had suffered lots of failures by then.

[rainersigwald]

@RobSwDev we don't expect a change in MSBuild itself to have caused this--nothing I can think of would have. So I like the "Windows changed" theory--but if the platform has changed, we should probably reconsider the "no point in retrying on ERROR_ACCESS_DENIED" assumption. As it was, that could speed up an extremely-likely-to-fail build. But if it also now makes likely-to-succeed-on-retry builds fail, that's not necessarily a good tradeoff. So we'd love to root-cause the change, but we're going ahead with #9217 so it's at least suppressible.