Regression with published application: PlatformNotSupportedException

Describe the bug

We have a .NET core application that is built and published inside a dockerfile. When we upgraded EF core to 3.1 and deployed our app, it started crashing at runtime in the SqlClient constructor with a PlatformNotSupportedException. After some investigation we determined the issue is related to how SqlClient is deployed with dotnet publish; also upgrading only SqlClient in isolation would result in the same crash. Running a shell inside the docker image it appears the correct SqlClient DLL for the platform (Linux) is not copied to the root of the application.

One workaround is to remove the --runtime linux-x64 flag from dotnet publish. Then it works. But this produces a different type of build (not self contained).

Exception message:
System.PlatformNotSupportedException: Microsoft.Data.SqlClient is not supported on this platform.

Stack trace:   
at Microsoft.Data.SqlClient.SqlConnection..ctor(String connectionString)
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerConnection.CreateDbConnection()
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.get_DbConnection()
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.CreateCommand(RelationalCommandParameterObject parameterObject, Guid commandId, DbCommandMethod commandMethod)
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReader(RelationalCommandParameterObject parameterObject)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.Enumerator.InitializeReader(DbContext _, Boolean result)
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.Enumerator.MoveNext()
   at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
   at System.Linq.Queryable.First[TSource](IQueryable`1 source)
   at EFGetStarted.Program.Main(String[] args) in /src/Program.cs:line 14

To reproduce

Clone this repo: https://github.com/davedx/sqlclient-repro

Then run:

docker build -t efgs -f ./Dockerfile.custom.dotnet.3.1 .

docker run efgs

Expected behavior

Previous to upgrading SqlClient, this dockerfile and deploy process worked and app would run without crashing.

Further technical details

Microsoft.Data.SqlClient version: 1.0.19269.1 .NET target: (Core 3.1) SQL Server version: (SQL Server 2019) Operating system: (Docker container)

Additional context

There seems to be a related issue here: https://github.com/dotnet/runtime/issues/29522

But we are on a newer version of dotnet core than the version in the above issue that fixed the issue. I’m happy to also open an issue no that repo if you think it’s an issue with a different component but thought I had to start somewhere. 😃

[davedx]

Hi @cheenamalhotra,

Thanks a lot for following up on this issue, it’s appreciated. I confirm this is caused by the sdk’s behaviour and it’s not sqlclient’s fault 😃 Maybe it would be nice to add a line about this to the FAQ entry for PlatformNotSupported Exception to help future travellers. Have a good week.

[cheenamalhotra]

Hi @davedx

As per comment https://github.com/dotnet/runtime/issues/33046#issuecomment-593714200 this behavior is by design. Let me know for any more questions you have.