Assembly 'Serilog.Settings.Configuration' produced trim warnings => Runtime error

[BPodszun]

I'm trying to build a self-contained, trimmed application that should be able to use Serilog.Sinks.Console and Serilog.Sinks.EventLog. I'm targeting dotnet8 and use the latest (at the time of this writing) versions of the relevant Serilog nuget packages.

The application works if I either

• run the unpublished version
• disable PublishTrimmed The latter is painful, because size matters for this project and the 12M executable balloons into nearly 70M without trimming.

Warning during compilation:

C:\Users\Ben.nuget\packages\serilog.settings.configuration\8.0.0\lib\net8.0\Serilog.Settings.Configuration.dll : warning IL2104: Assembly 'Serilog.Settings.Configuration' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries C:\Users\Ben.nuget\packages\serilog\3.1.1\lib\net7.0\Serilog.dll : warning IL2104: Assembly 'Serilog' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries

Runtime error (as stated above, it works without trimming):

Unhandled exception. System.IO.FileNotFoundException:
IO_FileName_Name, Serilog.Sinks.Console, Culture=neutral, PublicKeyToken=null
   at System.Reflection.RuntimeAssembly.<InternalLoad>g____PInvoke|49_0(NativeAssemblyNameParts*, ObjectHandleOnStack, StackCrawlMarkHandle, Int32, ObjectHandleOnStack, ObjectHandleOnStack)
   at System.Reflection.RuntimeAssembly.InternalLoad(NativeAssemblyNameParts*, ObjectHandleOnStack, StackCrawlMarkHandle, Boolean , ObjectHandleOnStack, ObjectHandleOnStack)
   at System.Reflection.RuntimeAssembly.InternalLoad(AssemblyName, StackCrawlMark&, AssemblyLoadContext , RuntimeAssembly , Boolean )
   at System.Reflection.Assembly.Load(AssemblyName)
   at Serilog.Settings.Configuration.ConfigurationReader.LoadConfigurationAssemblies(IConfiguration, AssemblyFinder)
   at Serilog.Settings.Configuration.ConfigurationReader..ctor(IConfiguration, AssemblyFinder, ConfigurationReaderOptions, IConfiguration )
   at Serilog.ConfigurationLoggerConfigurationExtensions.GetConfigurationReader(IConfiguration, ConfigurationReaderOptions, DependencyContext )
   at Serilog.ConfigurationLoggerConfigurationExtensions.Configuration(LoggerSettingsConfiguration, IConfiguration, ConfigurationReaderOptions )

My config, in case it matters:

{
  "Serilog": {
    "Using": [ "Serilog", "Serilog.Sinks.Console", "Serilog.Settings.Configuration" ],
    "MinimumLevel": "Debug",
    "WriteTo": [
      { "Name": "Console" }
    ],
    "Enrich": [ "FromLogContext", "WithMachineName", "WithThreadId" ]
  }
}

Code to initialize the logger:

var defaultAppSettingsStream = Assembly.GetExecutingAssembly().GetManifestResourceStream("Updater.appsettings.default.json");
var configuration = new ConfigurationBuilder()
  .SetBasePath(AppContext.BaseDirectory)
  .AddJsonStream(defaultAppSettingsStream)
  .Build();
return new LoggerConfiguration().ReadFrom.Configuration(configuration).CreateLogger();

Is there any way to make this work WITH trimming? Things I tried:

• explicitly listing the using references (see above)
• reverting back to the previous bundling behavior with <IncludeAllContentForSelfExtract>true</IncludeAllContentForSelfExtract> (the closed https://github.com/serilog-mssql/serilog-sinks-mssqlserver/issues/331 seems to refer to the same problem - the workaround in there doesn't work)
• explicitly passing ConfigurationAssemblySource.AlwaysScanDllFiles into ReadFrom.Configuration and all combinations I could think of

[bartelink]

Ordinarily I'd be saying "better to ask on SO as it's got v little to do with this package". In this case, you have provided good detail and having a story wrt trimming for this package is probably a good idea at some point, so it's not invalid to ask. However, I would suggest duplicating this question on SO with a link to here as the chances are you'll get more useful viewers there (vs the watchers on this repo, who watch there too, and will rarely have time to go off and investigate/comment knowledgeably on a question like this) are higher (and some people are happier to chuck in a quick answer and/or drive by comment that might be useful there vs here)

[BPodszun]

Thank you for your reply. I solved most of this using a combination of (in my csproj)

<IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>

(already existed in my project, note that I don't use IncludeAllContentForSelfExtract here)

and explicitly excluding all Serilog files from trimming¹

<ItemGroup>
  <TrimmerRootDescriptor Include="TrimmerRoots.xml" />
</ItemGroup>

where TrimmerRoots.xml is this for me:

<?xml version="1.0" encoding="utf-8" ?>
<linker>
  <assembly fullname="Serilog" />
  <assembly fullname="Serilog.Settings.Configuration" />
  <assembly fullname="Serilog.Sinks.Console" />
  <assembly fullname="Serilog.Sinks.EventLog" />
</linker>

①: https://devblogs.microsoft.com/dotnet/customizing-trimming-in-net-core-5/#using-xml-files-to-control-trimming

[BPodszun]

In case anyone ever runs into the above and stumbles along the same path: I'm still having issues to get the EventLog sink to work and filed https://github.com/serilog/serilog-sinks-eventlog/issues/51 (and asked on SO in parallel, as suggested)

[darklajid]

Actually, after quite some time of trying to get to the bottom of this I'm stuck looking at https://github.com/serilog/serilog-settings-configuration/blob/dev/src/Serilog.Settings.Configuration/Settings/Configuration/ConfigurationReader.cs#L460 now, which IS in this repository. It seems that in my case it does find the two extension methods that Serilog.Sinks.EventLog provides, but cannot match which one to use because ... the parameter names are empty via Reflection or something? Is this something that would be interesting for this repository/project to look into, is this a "bug" or at least a potential hard limitation to take note of?

[sungam3r]

@darklajid I suggest to open new issue.