Add error for incorrect PublishSelfContained

src/Tasks/Common/Resources/Strings.resx

@@ -981,9 +981,13 @@ You may need to build the project on another operating system or architecture, o
     <value>NETSDK1224: ASP.NET Core framework assets are not supported for the target framework.</value>
     <comment>{StrBegins="NETSDK1224: "}</comment>
   </data>
-  <!-- The latest message added is NativeCompilationRequiresPublishing. Please update this value with each PR to catch parallel PRs both adding a new message -->
   <data name="NativeCompilationRequiresPublishing" xml:space="preserve">
     <value>NETSDK1225: Native compilation is not supported when invoking the Publish target directly. Try running dotnet publish.</value>
     <comment>{StrBegins="NETSDK1225: "}</comment>
   </data>
+  <!-- The latest message added is PublishSelfContainedRequiresPublishing. Please update this value with each PR to catch parallel PRs both adding a new message -->
+  <data name="PublishSelfContainedRequiresPublishing" xml:space="preserve">
+    <value>NETSDK1226: PublishSelfContained is not supported when invoking the Publish target directly. Try running dotnet publish, or set SelfContained to true.</value>
+    <comment>{StrBegins="NETSDK1226: "}</comment>
+  </data>
 </root>

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Publish.targets

@@ -219,6 +219,12 @@ Copyright (c) .NET Foundation. All rights reserved.
                  ResourceName="SolutionProjectConfigurationsConflict"
                  FormatArguments="PublishRelease;$(ProjectName)"/>
 
+    <NETSdkError Condition="'$(PublishSelfContained)' == 'true' and
+                            '$(_IsPublishing)' != 'true' and
+                            '$(SelfContained)' != 'true' and
+                            '$(_TargetFrameworkVersionWithoutV)' >= '10.0'"
+                 ResourceName="PublishSelfContainedRequiresPublishing" />
+
     <NETSdkError Condition="'$(PublishAot)' == 'true' and
                             '$(_IsPublishing)' != 'true' and
                             '$(PublishAotUsingRuntimePack)' == 'true' and

test/Microsoft.NET.Publish.Tests/GivenThatWeWantToPublishASingleFileApp.cs

@@ -292,6 +292,7 @@ public void No_runtime_files()
                 Name = "SingleFileTest",
                 TargetFrameworks = ToolsetInfo.CurrentTargetFramework,
                 IsExe = true,
+                SelfContained = "true"
             };
 
             var testAsset = _testAssetsManager.CreateTestProject(testProject);
@@ -325,6 +326,7 @@ public void It_supports_composite_r2r(bool extractAll)
                 Name = projName,
                 TargetFrameworks = ToolsetInfo.CurrentTargetFramework,
                 IsExe = true,
+                SelfContained = "true"
             };
 
             var testAsset = _testAssetsManager.CreateTestProject(testProject);
@@ -769,7 +771,8 @@ private TestProject CreateTestProjectWithAnalyzerWarnings(string targetFramework
             {
                 Name = projectName,
                 TargetFrameworks = targetFramework,
-                IsExe = isExecutable
+                IsExe = isExecutable,
+                SelfContained = "true"
             };
 
             testProject.SourceFiles[$"{projectName}.cs"] = @"
@@ -850,6 +853,7 @@ public void It_can_disable_cetcompat(bool? cetCompat)
                 TargetFrameworks = ToolsetInfo.CurrentTargetFramework,
                 RuntimeIdentifier = rid,
                 IsExe = true,
+                SelfContained = "true"
             };
             if (cetCompat.HasValue)
             {
@@ -981,6 +985,7 @@ public void It_does_not_compress_single_file_by_default()
                 Name = "SingleFileTest",
                 TargetFrameworks = ToolsetInfo.CurrentTargetFramework,
                 IsExe = true,
+                SelfContained = "true"
             };
 
             var testAsset = _testAssetsManager.CreateTestProject(testProject);

test/Microsoft.NET.Publish.Tests/GivenThatWeWantToPublishASingleFileLibrary.cs

@@ -24,7 +24,8 @@ public void ItPublishesSuccessfullyWithRIDAndPublishSingleFileLibrary()
             TestProject testProject = new("MainProject")
             {
                 TargetFrameworks = targetFramework,
-                IsExe = true
+                IsExe = true,
+                SelfContained = "true"
             };
             testProject.ReferencedProjects.Add(referencedProject);
             testProject.RecordProperties("RuntimeIdentifier");