Make environment-derived properties change opt-in and read at use time (dotnet#7715)

Forgind · web-flow · commit 7a0fefe241f1 · 2022-06-20T16:09:18.000-05:00
This works around VS test failures in C++ scenarios that expected to see environment variables logged.
diff --git a/src/Build.UnitTests/BinaryLogger_Tests.cs b/src/Build.UnitTests/BinaryLogger_Tests.cs
@@ -144,6 +144,7 @@ public void UnusedEnvironmentVariablesDoNotAppearInBinaryLog()
         {
             using (TestEnvironment env = TestEnvironment.Create())
             {
+                env.SetEnvironmentVariable("MSBUILDONLYLOGUSEDENVIRONMENTVARIABLES", "1");
                 env.SetEnvironmentVariable("EnvVar1", "itsValue");
                 env.SetEnvironmentVariable("EnvVar2", "value2");
                 env.SetEnvironmentVariable("EnvVar3", "value3");
diff --git a/src/Framework/Traits.cs b/src/Framework/Traits.cs
@@ -94,7 +94,7 @@ public Traits()
         /// <summary>
         /// Log all environment variables whether or not they are used in a build in the binary log.
         /// </summary>
-        public readonly bool LogAllEnvironmentVariables = !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("MSBUILDLOGALLENVIRONMENTVARIABLES"))
+        public bool LogAllEnvironmentVariables => string.IsNullOrEmpty(Environment.GetEnvironmentVariable("MSBUILDONLYLOGUSEDENVIRONMENTVARIABLES"))
 #if !TASKHOST
             && ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave17_4)
 #endif

Original file line number	Diff line number	Diff line change
`@@ -144,6 +144,7 @@ public void UnusedEnvironmentVariablesDoNotAppearInBinaryLog()`
`144`	`144`	`{`
`145`	`145`	`using (TestEnvironment env = TestEnvironment.Create())`
`146`	`146`	`{`
	`147`	`+ env.SetEnvironmentVariable("MSBUILDONLYLOGUSEDENVIRONMENTVARIABLES", "1");`
`147`	`148`	`env.SetEnvironmentVariable("EnvVar1", "itsValue");`
`148`	`149`	`env.SetEnvironmentVariable("EnvVar2", "value2");`
`149`	`150`	`env.SetEnvironmentVariable("EnvVar3", "value3");`