Generate correct error message when trying to install a workload whic…

…h isn't supported for the current platform

src/Cli/dotnet/commands/dotnet-workload/install/WorkloadInstallCommand.cs

@@ -104,16 +104,16 @@ private void ValidateWorkloadIdsInput()
             var availableWorkloads = _workloadResolver.GetAvailableWorkloads();
             foreach (var workloadId in _workloadIds)
             {
-                if (availableWorkloads.Select(workload => workload.Id.ToString()).Contains(workloadId))
+                if (!availableWorkloads.Select(workload => workload.Id.ToString()).Contains(workloadId))
                 {
-                    if (!_workloadResolver.IsWorkloadPlatformCompatible(new WorkloadId(workloadId)))
+                    if (_workloadResolver.IsPlatformIncompatibleWorkload(new WorkloadId(workloadId)))
                     {
                         throw new GracefulException(string.Format(LocalizableStrings.WorkloadNotSupportedOnPlatform, workloadId));
                     }
-                }
-                else
-                {
-                    throw new GracefulException(string.Format(LocalizableStrings.WorkloadNotRecognized, workloadId));
+                    else
+                    {
+                        throw new GracefulException(string.Format(LocalizableStrings.WorkloadNotRecognized, workloadId));
+                    }
                 }
             }
         }

src/Resolvers/Microsoft.NET.Sdk.WorkloadManifestReader/IWorkloadResolver.cs

@@ -11,7 +11,7 @@ public interface IWorkloadResolver
         IEnumerable<WorkloadPackId> GetPacksInWorkload(WorkloadId workloadId);
         ISet<WorkloadResolver.WorkloadInfo>? GetWorkloadSuggestionForMissingPacks(IList<WorkloadPackId> packId, out ISet<WorkloadPackId> unsatisfiablePacks);
         IEnumerable<WorkloadResolver.WorkloadInfo> GetAvailableWorkloads();
-        bool IsWorkloadPlatformCompatible(WorkloadId workloadId);
+        bool IsPlatformIncompatibleWorkload(WorkloadId workloadId);
         string GetManifestVersion(string manifestId);
         IEnumerable<WorkloadResolver.ManifestInfo> GetInstalledManifests();
 

src/Resolvers/Microsoft.NET.Sdk.WorkloadManifestReader/WorkloadResolver.cs

@@ -621,13 +621,14 @@ public WorkloadInfo GetWorkloadInfo(WorkloadId workloadId)
             return new WorkloadInfo(workload.Id, workload.Description);
         }
 
-        public bool IsWorkloadPlatformCompatible(WorkloadId workloadId)
+        public bool IsPlatformIncompatibleWorkload(WorkloadId workloadId)
         {
             if (_workloads.TryGetValue(workloadId) is not (WorkloadDefinition workload, WorkloadManifest manifest))
             {
-                throw new ArgumentException($"Workload '{workloadId}' not found", nameof(workloadId));
+                //  Not a recognized workload
+                return false;
             }
-            return IsWorkloadPlatformCompatible(workload, manifest);
+            return !IsWorkloadPlatformCompatible(workload, manifest);
         }
 
         private bool IsWorkloadPlatformCompatible(WorkloadDefinition workload, WorkloadManifest manifest)

src/Tests/dotnet-workload-search.Tests/MockWorkloadResolver.cs

@@ -23,7 +23,7 @@ public MockWorkloadResolver(IEnumerable<WorkloadResolver.WorkloadInfo> available
         public ISet<WorkloadResolver.WorkloadInfo> GetWorkloadSuggestionForMissingPacks(IList<WorkloadPackId> packId, out ISet<WorkloadPackId> unsatisfiablePacks) => throw new NotImplementedException();
         public void RefreshWorkloadManifests() => throw new NotImplementedException();
         public WorkloadResolver.PackInfo TryGetPackInfo(WorkloadPackId packId) => throw new NotImplementedException();
-        public bool IsWorkloadPlatformCompatible(WorkloadId workloadId) => throw new NotImplementedException();
+        public bool IsPlatformIncompatibleWorkload(WorkloadId workloadId) => throw new NotImplementedException();
         public string GetManifestVersion(string manifestId) => throw new NotImplementedException();
         public IEnumerable<WorkloadResolver.ManifestInfo> GetInstalledManifests() => throw new NotImplementedException();
         public IWorkloadResolver CreateOverlayResolver(IWorkloadManifestProvider overlayManifestProvider) => throw new NotImplementedException();