Endpoints containing sagas fail to start when a scanned assembly contains a ref struct

[SimonCropp]

Symptoms

Endpoints fail to start and a System.TypeLoadException is logged indicating that a ref struct type violates the constraint of a type parameter.

Who's affected

You are affected if you have endpoints containing sagas and a scanned assembly contains a ref struct.

Root cause

Checking whether a type is a saga timeout does not consider that ref struct is not valid as generic type arguments.

Original Bug Report

Since MakeGenericType is used without checking if the type constraints are met

Steps to reproduce

Have a Ref struct in message scanning

NSB 9.2.2.0
.net: 8

Backported to

• 9.1.2
• 9.0.4
• 8.2.4
• 7.8.6

[SimonCropp]

it is a side effect of

transport.RouteToEndpoint(Assembly)

it doesn't seem to respect the message convention. so if u have any type in that assembly that conflicts with a type constraint it will blow up.

repo: https://github.com/SimonCropp/NSBGreedyRoutTo

[SimonCropp]

stack:

System.Exception: Failed to evaluate Message convention. See inner exception for details.
 ---> System.ArgumentException: GenericArguments[0], 'My.Messages.RefStruct', on 'NServiceBus.IHandleTimeouts`1[T]' violates the constraint of type 'T'.
 ---> System.TypeLoadException: GenericArguments[0], 'My.Messages.RefStruct', on 'NServiceBus.IHandleTimeouts`1[T]' violates the constraint of type parameter 'T'.
   at System.RuntimeTypeHandle.Instantiate(RuntimeType inst)
   at System.RuntimeType.MakeGenericType(Type[] instantiation)
   --- End of inner exception stack trace ---
   at System.RuntimeType.ValidateGenericArguments(MemberInfo definition, RuntimeType[] genericArguments, Exception e)
   at System.RuntimeType.MakeGenericType(Type[] instantiation)
   at NServiceBus.Features.Sagas.IsTypeATimeoutHandledByAnySaga(Type type, IEnumerable`1 sagas) in /_/src/NServiceBus.Core/Sagas/Sagas.cs:line 107
   at NServiceBus.Features.Sagas.<>c__DisplayClass0_0.<.ctor>b__4(Type t) in /_/src/NServiceBus.Core/Sagas/Sagas.cs:line 25
   at NServiceBus.Conventions.<>c__DisplayClass2_0.<IsInSystemConventionList>b__0(Func`2 isSystemMessageAction) in /_/src/NServiceBus.Core/Conventions/Conventions.cs:line 90
   at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source, Func`2 predicate)
   at NServiceBus.Conventions.IsInSystemConventionList(Type t) in /_/src/NServiceBus.Core/Conventions/Conventions.cs:line 90
   at NServiceBus.Conventions.<IsMessageType>b__1_0(RuntimeTypeHandle typeHandle) in /_/src/NServiceBus.Core/Conventions/Conventions.cs:line 37
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at NServiceBus.Conventions.ConventionCache.ApplyConvention(Type type, Func`2 action) in /_/src/NServiceBus.Core/Conventions/Conventions.cs:line 266
   at NServiceBus.Conventions.IsMessageType(Type t) in /_/src/NServiceBus.Core/Conventions/Conventions.cs:line 32
   --- End of inner exception stack trace ---
   at NServiceBus.Conventions.IsMessageType(Type t) in /_/src/NServiceBus.Core/Conventions/Conventions.cs:line 80
   at NServiceBus.AssemblyRouteSource.<>c__DisplayClass3_0.<GenerateRoutes>b__0(Type t) in /_/src/NServiceBus.Core/Routing/AssemblyRouteSource.cs:line 23
   at System.Linq.Enumerable.WhereSelectArrayIterator`2.ToArray()
   at NServiceBus.AssemblyRouteSource.GenerateRoutes(Conventions conventions) in /_/src/NServiceBus.Core/Routing/AssemblyRouteSource.cs:line 22
   at NServiceBus.Features.ConfiguredUnicastRoutes.Apply(UnicastRoutingTable unicastRoutingTable, Conventions conventions) in /_/src/NServiceBus.Core/Routing/ConfiguredUnicastRoutes.cs:line 23
   at NServiceBus.RoutingComponent.Initialize(Configuration configuration, Configuration receiveConfiguration, Conventions conventions, PipelineSettings pipelineSettings, Configuration hostingConfiguration, TransportSeam transportSeam) in /_/src/NServiceBus.Core/Routing/RoutingComponent.cs:line 36
   at NServiceBus.EndpointCreator.Configure() in /_/src/NServiceBus.Core/EndpointCreator.cs:line 86
   at NServiceBus.EndpointCreator.Create(EndpointConfiguration endpointConfiguration, IServiceCollection serviceCollection) in /_/src/NServiceBus.Core/EndpointCreator.cs:line 34
   at NServiceBus.Endpoint.Create(EndpointConfiguration configuration, CancellationToken cancellationToken) in /_/src/NServiceBus.Core/Endpoint.cs:line 24

[SimonCropp]

@boblangley what was the outcome of the Triage?

[boblangley]

We ranked it as a priority bug, but not critical. This means we have queued it for work with the other priority bugs and a team will take this on when one becomes available to work on it. I don't have an ETA, the team should say something on this issue when they start working on it.

[andreasohlund]

Thanks @SimonCropp we are working on a fix for this #7187

[SimonCropp]

@andreasohlund thanks

[andreasohlund]

@SimonCropp we're doing some more testing but if you want to play with 9.2.3 in advance to verify that you issue is solved you can get it here https://feedz.io/org/particular-software/repository/packages/packages/NServiceBus/9.2.3

[andreasohlund]

This has now been released, thanks for the detailed bug report @SimonCropp

[SimonCropp]

@andreasohlund @boblangley thanks peeps