Declaration referenced in a method implementation cannot be a final method. Npgsql.NpgsqlBatchCommandCollection

[pbiggar]

I get this exception when starting my app after upgrading to npgsql 6.0.0-preview7 with .NET6 RC1.

Unhandled exception. System.AggregateException: One or more errors occurred. (Declaration referenced in a method implementation cannot be a final method.  Type: 'Npgsql.NpgsqlBatchCommandCollection'.  Assembly: 'Npgsql, Version=6.0.0.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7'.)
 ---> System.TypeLoadException: Declaration referenced in a method implementation cannot be a final method.  Type: 'Npgsql.NpgsqlBatchCommandCollection'.  Assembly: 'Npgsql, Version=6.0.0.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7'.
   at Npgsql.PostgresDatabaseInfo.LoadBackendTypes(NpgsqlConnector conn, NpgsqlTimeout timeout, Boolean async)

Full stack trace:

Details

Unhandled exception. System.AggregateException: One or more errors occurred. (Declaration referenced in a method implementation cannot be a final method. Type: 'Npgsql.NpgsqlBatchCommandCollection'. Assembly: 'Npgsql, Version=6.0.0.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7'.) ---> System.TypeLoadException: Declaration referenced in a method implementation cannot be a final method. Type: 'Npgsql.NpgsqlBatchCommandCollection'. Assembly: 'Npgsql, Version=6.0.0.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7'. at Npgsql.PostgresDatabaseInfo.LoadBackendTypes(NpgsqlConnector conn, NpgsqlTimeout timeout, Boolean async) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at Npgsql.PostgresDatabaseInfo.LoadBackendTypes(NpgsqlConnector conn, NpgsqlTimeout timeout, Boolean async) at Npgsql.PostgresDatabaseInfo.LoadPostgresInfo(NpgsqlConnector conn, NpgsqlTimeout timeout, Boolean async) at Npgsql.PostgresDatabaseInfoFactory.Load(NpgsqlConnector conn, NpgsqlTimeout timeout, Boolean async) at Npgsql.Internal.NpgsqlDatabaseInfo.Load(NpgsqlConnector conn, NpgsqlTimeout timeout, Boolean async) at Npgsql.Internal.NpgsqlConnector.LoadDatabaseInfo(Boolean forceReload, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken) at Npgsql.Internal.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken) at Npgsql.ConnectorPool.OpenNewConnector(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken) at Npgsql.ConnectorPool.g__RentAsync|29_0(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken) at Npgsql.NpgsqlConnection.g__OpenAsync|45_0(Boolean async, CancellationToken cancellationToken) at Npgsql.FSharp.Sql.executeNonQueryAsync@477-3.Invoke(Unit unitVar0) at Ply.TplPrimitives.AwaitableContinuation`3.Invoke(Unit r) at Ply.TplPrimitives.combine@240.Invoke(AwaitableContinuation`3 this) at Ply.TplPrimitives.AwaitableContinuation`3.Invoke(Unit r) at Ply.TplPrimitives.tryFinally@257.Invoke(AwaitableContinuation`3 this) at Ply.TplPrimitives.ContinuationStateMachine`1.System-Runtime-CompilerServices-IAsyncStateMachine-MoveNext() at LibBackend.Db.Sql.executeStatementAsync@69-2.Invoke(Unit unitVar0) in /home/dark/app/fsharp-backend/src/LibBackend/Db.fs:line 69 at Ply.TplPrimitives.ContinuationStateMachine`1.System-Runtime-CompilerServices-IAsyncStateMachine-MoveNext() at Prelude.Task.map@1134-4.Invoke(Unit unitVar0) in /home/dark/app/fsharp-backend/src/Prelude/Prelude.fs:line 1134 at Ply.TplPrimitives.ContinuationStateMachine`1.System-Runtime-CompilerServices-IAsyncStateMachine-MoveNext() at LibBackend.Account.upsertAccount@143-4.Invoke(Unit unitVar0) in /home/dark/app/fsharp-backend/src/LibBackend/Account.fs:line 143 at Ply.TplPrimitives.ContinuationStateMachine`1.System-Runtime-CompilerServices-IAsyncStateMachine-MoveNext() at LibBackend.Account.initTestAccounts@352-6.Invoke(Unit unitVar0) in /home/dark/app/fsharp-backend/src/LibBackend/Account.fs:line 352 at Ply.TplPrimitives.ContinuationStateMachine`1.System-Runtime-CompilerServices-IAsyncStateMachine-MoveNext() --- End of inner exception stack trace --- at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions) at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken) at System.Threading.Tasks.Task.Wait() at Tests.All.main(String[] args) in /home/dark/app/fsharp-backend/tests/Tests/Tests.fs:line 17

Steps to reproduce

It can be reproduced pretty easily in our repo, using this commit: darklang/dark@6e3b151. If you want to check it out, running ./scripts/builder --watch --compile --test from a clean checkout should hit the error.

Further technical details

Npgsql version: 6.0.0-preview7
PostgreSQL version: 9.6
Operating system: Linux
.NET: 6.0.100-rc.1.21417.9"

[roji]

@pbiggar there was a change to the batching API merged for rc1, which is most probably the source of this issue. Use Npgsql 6.0.0-preview7 with the corresponding dotnet SDK 6.0.0-preview7 - Npgsql 6.0.0-rc1 will be compatible with dotnet SDK 6.0.0-rc1.

[pbiggar]

Thanks for the clarification. Alas I can't use preview7 due to other dependency conflicts. Will look forward to npgsql rc1, thanks!