WIP

ref/Microsoft.Build/net/Microsoft.Build.cs

@@ -772,6 +772,7 @@ public enum ProjectLoadSettings
         DoNotEvaluateElementsWithFalseCondition = 32,
         IgnoreInvalidImports = 64,
         ProfileEvaluation = 128,
+        FailOnUnresolvedSdk = 256,
     }
     public partial class ProjectMetadata : System.IEquatable<Microsoft.Build.Evaluation.ProjectMetadata>
     {
@@ -1047,6 +1048,8 @@ public enum BuildRequestDataFlags
         SkipNonexistentTargets = 16,
         ProvideSubsetOfStateAfterBuild = 32,
         IgnoreMissingEmptyAndInvalidImports = 64,
+        SkipNonexistentNonTopLevelTargets = 128,
+        FailOnUnresolvedSdk = 256,
     }
     public partial class BuildResult
     {
@@ -1566,8 +1569,8 @@ public partial class GraphBuildOptions : System.IEquatable<Microsoft.Build.Graph
         public virtual bool Equals(Microsoft.Build.Graph.GraphBuildOptions other) { throw null; }
         public override bool Equals(object obj) { throw null; }
         public override int GetHashCode() { throw null; }
-        public static bool operator ==(Microsoft.Build.Graph.GraphBuildOptions r1, Microsoft.Build.Graph.GraphBuildOptions r2) { throw null; }
-        public static bool operator !=(Microsoft.Build.Graph.GraphBuildOptions r1, Microsoft.Build.Graph.GraphBuildOptions r2) { throw null; }
+        public static bool operator ==(Microsoft.Build.Graph.GraphBuildOptions left, Microsoft.Build.Graph.GraphBuildOptions right) { throw null; }
+        public static bool operator !=(Microsoft.Build.Graph.GraphBuildOptions left, Microsoft.Build.Graph.GraphBuildOptions right) { throw null; }
         protected virtual bool PrintMembers(System.Text.StringBuilder builder) { throw null; }
         public override string ToString() { throw null; }
         public virtual Microsoft.Build.Graph.GraphBuildOptions <Clone>$() { throw null; }

ref/Microsoft.Build/netstandard/Microsoft.Build.cs

@@ -772,6 +772,7 @@ public enum ProjectLoadSettings
         DoNotEvaluateElementsWithFalseCondition = 32,
         IgnoreInvalidImports = 64,
         ProfileEvaluation = 128,
+        FailOnUnresolvedSdk = 256,
     }
     public partial class ProjectMetadata : System.IEquatable<Microsoft.Build.Evaluation.ProjectMetadata>
     {
@@ -1042,6 +1043,8 @@ public enum BuildRequestDataFlags
         SkipNonexistentTargets = 16,
         ProvideSubsetOfStateAfterBuild = 32,
         IgnoreMissingEmptyAndInvalidImports = 64,
+        SkipNonexistentNonTopLevelTargets = 128,
+        FailOnUnresolvedSdk = 256,
     }
     public partial class BuildResult
     {
@@ -1560,8 +1563,8 @@ public partial class GraphBuildOptions : System.IEquatable<Microsoft.Build.Graph
         public virtual bool Equals(Microsoft.Build.Graph.GraphBuildOptions other) { throw null; }
         public override bool Equals(object obj) { throw null; }
         public override int GetHashCode() { throw null; }
-        public static bool operator ==(Microsoft.Build.Graph.GraphBuildOptions r1, Microsoft.Build.Graph.GraphBuildOptions r2) { throw null; }
-        public static bool operator !=(Microsoft.Build.Graph.GraphBuildOptions r1, Microsoft.Build.Graph.GraphBuildOptions r2) { throw null; }
+        public static bool operator ==(Microsoft.Build.Graph.GraphBuildOptions left, Microsoft.Build.Graph.GraphBuildOptions right) { throw null; }
+        public static bool operator !=(Microsoft.Build.Graph.GraphBuildOptions left, Microsoft.Build.Graph.GraphBuildOptions right) { throw null; }
         protected virtual bool PrintMembers(System.Text.StringBuilder builder) { throw null; }
         public override string ToString() { throw null; }
         public virtual Microsoft.Build.Graph.GraphBuildOptions <Clone>$() { throw null; }

src/Build/BackEnd/BuildManager/BuildManager.cs

@@ -1702,6 +1702,11 @@ private void ExecuteGraphBuildScheduler(GraphBuildSubmission submission)
                                 projectLoadSettings |= ProjectLoadSettings.IgnoreMissingImports | ProjectLoadSettings.IgnoreInvalidImports | ProjectLoadSettings.IgnoreEmptyImports;
                             }
 
+                            if (submission.BuildRequestData.Flags.HasFlag(BuildRequestDataFlags.FailOnUnresolvedSdk))
+                            {
+                                projectLoadSettings |= ProjectLoadSettings.FailOnUnresolvedSdk;
+                            }
+
                             return new ProjectInstance(
                                 path,
                                 properties,

src/Build/BackEnd/BuildManager/BuildRequestData.cs

@@ -75,6 +75,15 @@ public enum BuildRequestDataFlags
         /// This is especially useful during a restore since some imports might come from packages that haven't been restored yet.
         /// </summary>
         IgnoreMissingEmptyAndInvalidImports = 1 << 6,
+
+        /// <summary>
+        /// When this flag is present, the top level target(s) in the build request will be skipped if those targets
+        /// are not defined in the Project to build. This only applies to this build request (if another target calls
+        /// the "missing target" at any other point this will still result in an error).
+        /// </summary>
+        SkipNonexistentNonTopLevelTargets = 1 << 7,
+
+        FailOnUnresolvedSdk = 1 << 8,
     }
 
     /// <summary>

src/Build/BackEnd/Components/RequestBuilder/TargetBuilder.cs

@@ -143,10 +143,12 @@ public async Task<BuildResult> BuildTargets(ProjectLoggingContext loggingContext
             foreach (string targetName in targetNames)
             {
                 var targetExists = _projectInstance.Targets.TryGetValue(targetName, out ProjectTargetInstance targetInstance);
-                if (!targetExists && entry.Request.BuildRequestDataFlags.HasFlag(BuildRequestDataFlags.SkipNonexistentTargets))
+                if (!targetExists
+                    && entry.Request.BuildRequestDataFlags.HasFlag(BuildRequestDataFlags.SkipNonexistentTargets)
+                    || entry.Request.BuildRequestDataFlags.HasFlag(BuildRequestDataFlags.SkipNonexistentNonTopLevelTargets) && !entry.Request.Targets.Contains(targetName))
                 {
                     _projectLoggingContext.LogComment(Framework.MessageImportance.Low,
-                        "TargetSkippedWhenSkipNonexistentTargets", targetName);
+                    "TargetSkippedWhenSkipNonexistentTargets", targetName);
                 }
                 else
                 {

src/Build/BackEnd/Shared/BuildRequestConfiguration.cs

@@ -466,6 +466,11 @@ private void SetProjectBasedState(ProjectInstance project)
                     projectLoadSettings |= ProjectLoadSettings.IgnoreMissingImports | ProjectLoadSettings.IgnoreInvalidImports | ProjectLoadSettings.IgnoreEmptyImports;
                 }
 
+                if (buildRequestDataFlags.HasFlag(buildRequestDataFlags & BuildRequestDataFlags.FailOnUnresolvedSdk))
+                {
+                    projectLoadSettings |= ProjectLoadSettings.FailOnUnresolvedSdk;
+                }
+
                 return new ProjectInstance(
                     ProjectFullPath,
                     globalProperties,

src/Build/Definition/ProjectLoadSettings.cs

@@ -59,5 +59,7 @@ public enum ProjectLoadSettings
         /// Whether to profile the evaluation
         /// </summary>
         ProfileEvaluation = 128,
+
+        FailOnUnresolvedSdk = 256,
     }
 }

src/Build/Evaluation/Evaluator.cs

@@ -1761,7 +1761,7 @@ private List<ProjectRootElement> ExpandAndLoadImports(string directoryOfImportin
 
                 if (!sdkResult.Success)
                 {
-                    if (_loadSettings.HasFlag(ProjectLoadSettings.IgnoreMissingImports))
+                    if (_loadSettings.HasFlag(ProjectLoadSettings.IgnoreMissingImports) && !_loadSettings.HasFlag(ProjectLoadSettings.FailOnUnresolvedSdk))
                     {
                         ProjectImportedEventArgs eventArgs = new ProjectImportedEventArgs(
                             importElement.Location.Line,

src/MSBuild/XMake.cs

@@ -1431,7 +1431,7 @@ private static (BuildResultCode result, Exception exception) ExecuteRestore(stri
                 toolsVersion,
                 targetsToBuild: new[] { MSBuildConstants.RestoreTargetName },
                 hostServices: null,
-                flags: BuildRequestDataFlags.ClearCachesAfterBuild | BuildRequestDataFlags.SkipNonexistentTargets | BuildRequestDataFlags.IgnoreMissingEmptyAndInvalidImports);
+                flags: BuildRequestDataFlags.ClearCachesAfterBuild | BuildRequestDataFlags.SkipNonexistentNonTopLevelTargets | BuildRequestDataFlags.IgnoreMissingEmptyAndInvalidImports | BuildRequestDataFlags.FailOnUnresolvedSdk);
 
             return ExecuteBuild(buildManager, restoreRequest);
         }