Fixed: suppress unhelpful warning in cibuild log

Author: Bart Koelman

test/TestBuildingBlocks/BaseIntegrationTestContext.cs

@@ -71,7 +71,15 @@ private WebApplicationFactory<TRemoteStartup> CreateFactory()
 
                 services.AddDbContext<TDbContext>(options =>
                 {
-                    options.UseNpgsql(dbConnectionString);
+                    options.UseNpgsql(dbConnectionString, builder =>
+                        // The next line suppresses EF Core Warning:
+                        //    "Compiling a query which loads related collections for more than one collection navigation
+                        //    either via 'Include' or through projection but no 'QuerySplittingBehavior' has been configured."
+                        // We'd like to use `QuerySplittingBehavior.SplitQuery` because of improved performance, but unfortunately
+                        // it makes EF Core 5 crash on queries that load related data in a projection without Include.
+                        // This is fixed in EF Core 6, tracked at https://github.com/dotnet/efcore/issues/21234.
+                        builder.UseQuerySplittingBehavior(QuerySplittingBehavior.SingleQuery));
+
                     options.EnableSensitiveDataLogging();
                     options.EnableDetailedErrors();
                 });