Flaky missing files in single FDD exe temp dir

[dedale]

Hello,

We have a .NET Core App 3.1 console application (AKA ysh) deployed as a single framework dependent executable. Based on our ELK metrics, this application is used hundreds of times a day.
But everyday, we have a few users facing failures like:

A fatal error was encountered. The library 'hostpolicy.dll' required to execute the application was not found in '<C:\Program Files\dotnet>'.

-- Invoked apphost [version: 3.1.2, commit hash: ... main = { %AppData%\Local\Temp\ysh.exe compile debug }
Redirecting errors to custom writer:
The managed DLL bound to this executable is: 'Ard.Ying.Shell.dll'
[...] --- Resolving hostpolicy.dll version from deps json

An assemby specified in the application dependencies manifest (Ard.Ying.Shell.deps.json) was not found:
Package: 'JetBrains.Annotations', version: '2019.1.3'
path: 'lib/netstandard2.0/JetBrains.Annotations.dll'

We currently advise these users to remove all %TEMP%/.net/ysh directories.

Unfortunately, even if I am the top user of this application, I am unable to reproduce the problem under normal conditions (of course, removing files in temp folder would trigger the failures).

Thanks in advance for your help.
Vianney

[janvorli]

cc: @vitek-karas

[ghost]

Tagging subscribers to this area: @swaroop-sridhar
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[swaroop-sridhar]

This is a dup of #3778

The bug will be fixed in this month's servicing release.
In the meantime, as a workaround, you can set the DOTNET_BUNDLE_EXTRACT_BASE_DIR environment variable to a non-temp directory when running the app, so that the extracted files are not cleaned up.