NullRef installing WebAssembly AOT workload on Linux

Writing workload pack installation record for Microsoft.NET.Runtime.Emscripten.Node version 6.0.0-preview.4.21220.1...
System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.DotNet.Workloads.Workload.Install.NetSdkManagedInstaller.GetPackInstallRecordPath(PackInfo packInfo, SdkFeatureBand featureBand) in dotnet.dll:token 0x60001c5+0x0
   at Microsoft.DotNet.Workloads.Workload.Install.NetSdkManagedInstaller.DeletePackInstallationRecord(PackInfo packInfo, SdkFeatureBand featureBand) in dotnet.dll:token 0x60001c7+0x0
   at Microsoft.DotNet.Workloads.Workload.Install.NetSdkManagedInstaller.RollBackWorkloadPackInstall(PackInfo packInfo, SdkFeatureBand sdkFeatureBand) in dotnet.dll:token 0x60001bd+0x0
   at Microsoft.DotNet.Workloads.Workload.Install.WorkloadInstallCommand.<>c__DisplayClass14_1.<InstallWorkloadsWithInstallRecord>b__3() in dotnet.dll:token 0x6000b20+0x15
   at Microsoft.DotNet.Cli.TransactionalAction.EnlistmentNotification.Rollback(Enlistment enlistment) in dotnet.dll:token 0x6000ced+0x8
   at System.Transactions.VolatileEnlistmentAborting.EnterState(InternalEnlistment enlistment) in System.Transactions.Local.dll:token 0x6000404+0x0
   at System.Transactions.VolatileEnlistmentActive.InternalAborted(InternalEnlistment enlistment) in System.Transactions.Local.dll:token 0x60003e9+0x0
   at System.Transactions.TransactionStateAborted.EnterState(InternalTransaction tx) in System.Transactions.Local.dll:token 0x6000259+0x4c
   at System.Transactions.TransactionStateActive.Rollback(InternalTransaction tx, Exception e) in System.Transactions.Local.dll:token 0x6000224+0x8
   at System.Transactions.Transaction.Rollback() in System.Transactions.Local.dll:token 0x600010b+0x4b
   at System.Transactions.TransactionScope.InternalDispose() in System.Transactions.Local.dll:token 0x600019c+0x95
   at System.Transactions.TransactionScope.Dispose() in System.Transactions.Local.dll:token 0x600019b+0x34b
   at Microsoft.DotNet.Cli.TransactionalAction.Run[T](Func`1 action, Action commit, Action rollback) in dotnet.dll:token 0x6000922+0x47
   at Microsoft.DotNet.Cli.TransactionalAction.Run(Action action, Action commit, Action rollback) in dotnet.dll:token 0x6000923+0x19
   at Microsoft.DotNet.Workloads.Workload.Install.WorkloadInstallCommand.InstallWorkloadsWithInstallRecord(IEnumerable`1 workloadIds, SdkFeatureBand sdkFeatureBand) in dotnet.dll:token 0x60001cf+0xb5
   at Microsoft.DotNet.Workloads.Workload.Install.WorkloadInstallCommand.InstallWorkloads(IEnumerable`1 workloadIds, Boolean skipManifestUpdate) in dotnet.dll:token 0x60001ce+0x58
   at Microsoft.DotNet.Workloads.Workload.Install.WorkloadInstallCommand.Execute() in dotnet.dll:token 0x60001cb+0x216
   at Microsoft.DotNet.Cli.DotNetTopLevelCommandBase.RunCommand(String[] args) in dotnet.dll:token 0x60008af+0x5e
   at Microsoft.DotNet.Workloads.Workload.WorkloadCommand.Run(String[] args) in dotnet.dll:token 0x6000145+0x6
   at Microsoft.DotNet.Cli.Program.ProcessArgs(String[] args, TimeSpan startupTime, ITelemetry telemetryClient) in dotnet.dll:token 0x6000918+0x2e8
   at Microsoft.DotNet.Cli.Program.Main(String[] args) in dotnet.dll:token 0x6000916+0x6f

[marcpopMSFT]

This should be fixed in preview 5.

[sfoslund]

I’ve found the issue, it’s related to https://github.com/dotnet/sdk/issues/17790. Basically, the install fails because the blazor workload does not define a linux package alias for the Microsoft.NET.Runtime.Emscripten.Python pack in their manifest file. As a result, the installation is failing and while we try to roll back we get another failure, which results in this confusing message. All of these issues have been fixed in preview 5: Issue causing the install failure/ roll back failure (no linux alias specified): https://github.com/dotnet/sdk/pull/17794 Logging improvement, for clearer error message: https://github.com/dotnet/sdk/pull/17233

For now with the buggy SDK version, the offending sections of the blazor manifest (sdk-manifests\6.0.100\Microsoft.NET.Workload.BlazorWebAssembly\WorkloadManifest.json) are:

    "Microsoft.NET.Runtime.Emscripten.Python" : {
      "kind": "Sdk",
      "version": "6.0.0-preview.4.21220.1",
      "alias-to": {
        "win-x86": "Microsoft.NET.Runtime.Emscripten.2.0.12.Python.win-x86",
        "win-x64": "Microsoft.NET.Runtime.Emscripten.2.0.12.Python.win-x64",
        "osx-x64": "Microsoft.NET.Runtime.Emscripten.2.0.12.Python.osx-x64"
      }
    },

and

        "Microsoft.NET.Runtime.Emscripten.Python",

So this issue can be worked around on linux by just removing these sections from the manifest file.