Sentry.Samples.AspNetCore.Serilog throws an exception after assigning a SamplesShared.Dsn and running

[jamescrosswell]

The steps are:

1. Load the sample as-is (I upgraded everything to net10.0 and the latest versions, but this error still occurs)
2. Assign SamplesShared.Dsn
3. Press F5
4. Observe error

Alternatively, modifying builder.WebHost.UseSentry(SamplesShared.Dsn) so that it reads from appSettings instead (builder.WebHost.UseSentry()), setting Sentry.Dsn here and pressing F5 also results in the same error.

Please let me know if I have misunderstood the above process.

Originally posted by @Mike-E-angelo in #5245

Related

• Consider not initialising the Sdk from logging integrations #5245

[linear-code]

NET-695

[dingsdax]

I've created a reproduction for this issue: getsentry/repro#50

The bug confirms that builder.Build() throws ArgumentNullException when using both builder.WebHost.UseSentry(dsn) and .WriteTo.Sentry(options => {...}) — the Serilog sink calls SentrySdk.Init() internally but the DSN configured via UseSentry() isn't available to it.

You can run it with:

# With Docker
docker build -t sentry-repro-5268 .
docker run --rm sentry-repro-5268

# Or with .NET SDK
dotnet run

🤖 Generated with Claude Code

[jamescrosswell]

@Mike-E-angelo / @dingsdax I acknowledge this is confusing (which is why we have #5245 open for the next major release) but in the repro you provided @dingsdax you've used this overload of the method to create a Sentry sink for Serilog:

sentry-dotnet/src/Sentry.Serilog/SentrySinkExtensions.cs

Lines 354 to 368 in d3d2f71

	public static LoggerConfiguration Sentry(
	this LoggerSinkConfiguration loggerConfiguration,
	Action<SentrySerilogOptions> configureOptions)
	{
	var options = new SentrySerilogOptions();
	configureOptions?.Invoke(options);
	IDisposable? sdkDisposable = null;
	if (options.InitializeSdk)
	{
	sdkDisposable = SentrySdk.Init(options);
	}
	return loggerConfiguration.Sink(new SentrySink(options, sdkDisposable));
	}

In particular, see line 362... it checks whether you want to initialize the SDK in the options (which defaults to true since that's how the SDK has always behaved historically - we added that as a non-breaking change):

sentry-dotnet/src/Sentry.Serilog/SentrySerilogOptions.cs

Line 12 in 2285a7f

public bool InitializeSdk { get; set; } = true;

So if you want to use this overload to initialize the SDK, you need to set that option to false by doing something like this:

        .WriteTo.Sentry(s =>
        {
            s.InitializeSdk = false;
            s.MinimumBreadcrumbLevel = LogEventLevel.Debug;
            s.MinimumEventLevel = LogEventLevel.Error;
        }));

Alternatively, there's another overload that accepts only the parameters that are relevant to Serilog here, which guarantees the Sink will be created without attempting to (re)initialise the Sentry SDK:

sentry-dotnet/src/Sentry.Serilog/SentrySinkExtensions.cs

Lines 172 to 178 in d3d2f71

	public static LoggerConfiguration Sentry(
	this LoggerSinkConfiguration loggerConfiguration,
	LogEventLevel? minimumEventLevel = null,
	LogEventLevel? minimumBreadcrumbLevel = null,
	IFormatProvider? formatProvider = null,
	ITextFormatter? textFormatter = null
	)

@Mike-E-angelo if you're still having issues and you've got another repro you want us to look at, please get back to us with that repro but closing this for the time being as, although the current SDK implementation is confusing, I don't think there are any functional issues with it.

[Mike-E-angelo]

Hi @jamescrosswell thank you for your investigation, and please pardon my confusion here. The issue is that the repro, as designed from your samples, results in an exception when following the basic instructions and pressing F5. This is not a confusion issue; it's a basic user experience issue, as this is the official guidance currently provided for onboarding your product. But also, yes, a confusion issue. 😅

The samples should use a configuration method so that when the basic instructions are followed, and F5 is pressed, no exception occurs. If an alternative overload is available and works, why is it not used in the samples? I hope that further explains this issue.

[jamescrosswell]

Ah, right... sorry I think you've mentioned that before @Mike-E-angelo - I think I just got discombobulated... reopening.