log4net crashes while creating mutex

[strpp]

We have a .NET Core 3.1 application running on Linux where we use log4net 2.0.12.
In the last two weeks, we run into this exception twice:

Unhandled exception. System.IO.IOException: The system cannot open the device or file specified. : '_opt_Dists_2025.1.1.h1_WorkingDirectories_8255_b44c8ce2-574b-48a2-8c4d-2aee273f9bf5_app.log'
   at System.Threading.Mutex.CreateMutexCore(Boolean initiallyOwned, String name, Boolean& createdNew)
   at System.Threading.Mutex..ctor(Boolean initiallyOwned, String name)
   at log4net.Appender.RollingFileAppender.ActivateOptions()

Some additional info:

• log folder name is unique since it is created at runtime using a guid (so mutex name should be unique too)
• log file is not even created
• bug is not deterministic, if we re run our app, everything goes fine

[FreeAndNil]

Hi @strpp please test with our latest version: https://github.com/apache/logging-log4net/releases/tag/rel%2F3.0.3 and .net 8.
log4net 2.x is no longer supported.
.Net Core 3.1 is no longer supported for more than two years.

[strpp]

Thanks for the reply but unfortunately we cannot update to .NET 8.
We'll try to use 2.0.17 version and later (if possible) we'll update to 3.0.3

[strpp]

Also, mutex creation in RollingFileAppender.ActivateOptions seems to not have changed in further versions (except for that _rolling appended to the mutex name) so I'm afraid updating won't solve the issue

[FreeAndNil]

@strpp the Mutex ctor can fail for many reasons on Linux (see PowerShell/PSReadLine#1464).
There are probably fixes (or better error messages) in the supported .net versions.