Unable to remove item by its PK only

If an entity has extra indices then I am unable to delete it by its PK only

Example

    class Program
    {
        static int Main(string[] args)
        {
            var ctx = new MyDbContext();

            **var toBeDeleted = ctx.RiskConsequenceSeverityGroupItems
                .Select(e => new RiskConsequenceSeverityGroupItem { Id = e.Id });**

            ctx.RiskConsequenceSeverityGroupItems.RemoveRange(toBeDeleted);

            ctx.SaveChanges();

            return 0;
        }
    }

    public class RiskConsequenceSeverityGroupItem
    {
        public int Id { get; set; }

        public int Order { get; set; }

        public string Name { get; set; }
    }

    public class MyDbContext : DbContext
    {
        public DbSet<RiskConsequenceSeverityGroupItem> RiskConsequenceSeverityGroupItems { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer("Server=localhost,1433;Database=ipl_tux;Integrated Security=True;");            
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<RiskConsequenceSeverityGroupItem>()
                .HasIndex(e => new { e.Order })
                .IsUnique();

            base.OnModelCreating(modelBuilder);
        }
    }

In this case I get the following execption

Unhandled Exception: System.ArgumentException: An item with the same key has already been added. Key: System.Object[] at System.ThrowHelper.ThrowAddingDuplicateWithKeyArgumentException(Object key) at System.Collections.Generic.Dictionary2.TryInsert(TKey key, TValue value, InsertionBehavior behavior) at System.Collections.Generic.Dictionary2.Add(TKey key, TValue value) at Microsoft.EntityFrameworkCore.Update.Internal.CommandBatchPreparer.AddUniqueValueEdges(Multigraph2 commandGraph) at Microsoft.EntityFrameworkCore.Update.Internal.CommandBatchPreparer.TopologicalSort(IEnumerable1 commands) at Microsoft.EntityFrameworkCore.Update.Internal.CommandBatchPreparer.<BatchCommands>d__8.MoveNext() at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.Execute(Tuple2 parameters) at Microsoft.EntityFrameworkCore.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func3 operation, Func3 verifySucceeded) at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.Execute[TState,TResult](IExecutionStrategy strategy, TState state, Func2 operation) at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.Execute(IEnumerable1 commandBatches, IRelationalConnection connection) at Microsoft.EntityFrameworkCore.Storage.RelationalDatabase.SaveChanges(IReadOnlyList1 entries) at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(IReadOnlyList`1 entriesToSave) at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(Boolean acceptAllChangesOnSuccess) at Microsoft.EntityFrameworkCore.DbContext.SaveChanges(Boolean acceptAllChangesOnSuccess) at Microsoft.EntityFrameworkCore.DbContext.SaveChanges() at EfTests.Program.Main(String[] args) in D:\code\tuxedo\Tests\EfBugTest.cs:line 17

However, if I specify the extra column which has an index on then it works fine

Example

            var toBeDeleted = ctx.RiskConsequenceSeverityGroupItems
                .Select(e => new RiskConsequenceSeverityGroupItem { Id = e.Id**, Order = e.Order** });

            ctx.RiskConsequenceSeverityGroupItems.RemoveRange(toBeDeleted);

            ctx.SaveChanges();

Having to specify that extra column seems to be irrelevant to me if all want to do is to delete it. It works even if I assign random numbers to it.

Example

            var toBeDeleted = ctx.RiskConsequenceSeverityGroupItems
                .Select(e => new RiskConsequenceSeverityGroupItem { Id = e.Id**, Order = new Random().Next()** });

            ctx.RiskConsequenceSeverityGroupItems.RemoveRange(toBeDeleted);

            ctx.SaveChanges();

[smitpatel]

Not a duplicate.

[ajcvickers]

Notes from triage: we will make the sorting robust to duplicates. This means that if the delete is happening on its own (and therefore does not require any ordering to succeed) then it will not fail. However, in the general case the values for the unique index must be known or the update pipeline could perform operations in the wrong order, and this will fail. It is up to the developer attaching the stub to understand whether attaching a stub without setting unique index values will be safe. If this cannot be determined, then always make sure these values are set.