Refactor SDK targets to address multiple writes and flaky builds (#1861)

Author: jviau

DotNetWorker.sln

@@ -134,6 +134,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Worker.Extensions.Tests", "
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AspNetIntegration", "samples\AspNetIntegration\AspNetIntegration.csproj", "{D2F67410-9933-42E8-B04A-E17634D83A30}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Net7Worker", "samples\Net7Worker\Net7Worker.csproj", "{EC1A321B-70F6-420B-85D4-56C7869BB71B}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -332,6 +334,10 @@ Global
 		{D2F67410-9933-42E8-B04A-E17634D83A30}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{D2F67410-9933-42E8-B04A-E17634D83A30}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{D2F67410-9933-42E8-B04A-E17634D83A30}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EC1A321B-70F6-420B-85D4-56C7869BB71B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EC1A321B-70F6-420B-85D4-56C7869BB71B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EC1A321B-70F6-420B-85D4-56C7869BB71B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EC1A321B-70F6-420B-85D4-56C7869BB71B}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -390,6 +396,7 @@ Global
 		{286F9EE3-00AE-4EFA-BFD8-A2E58BC809D2} = {FD7243E4-BF18-43F8-8744-BA1D17ACF378}
 		{17BDCE12-6964-4B87-B2AC-68CE270A3E9A} = {FD7243E4-BF18-43F8-8744-BA1D17ACF378}
 		{D2F67410-9933-42E8-B04A-E17634D83A30} = {9D6603BD-7EA2-4D11-A69C-0D9E01317FD6}
+		{EC1A321B-70F6-420B-85D4-56C7869BB71B} = {9D6603BD-7EA2-4D11-A69C-0D9E01317FD6}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {497D2ED4-A13E-4BCA-8D29-F30CA7D0EA4A}

sdk/Sdk/ExtensionsCsprojGenerator.cs

@@ -32,16 +32,13 @@ public void Generate()
             var extensionsCsprojFilePath = Path.Combine(_outputPath, ExtensionsProjectName);
 
             string csproj = GetCsProjContent();
-
-            // Incremental build support: write the new csproj only if contents have changed.
-            // By keeping one from a previous build around, our restore & build has a chance
-            // to follow incremental build and no-op if nothing needs to be done.
             if (File.Exists(extensionsCsprojFilePath))
             {
                 string existing = File.ReadAllText(extensionsCsprojFilePath);
                 if (string.Equals(csproj, existing, StringComparison.Ordinal))
                 {
-                    // Up to date, nothing to do.
+                    // If contents are the same, only touch the file to update timestamp.
+                    File.SetLastWriteTimeUtc(extensionsCsprojFilePath, DateTime.UtcNow);
                     return;
                 }
             }