[release/6.0-staging] dotnet.exe prints error messages to console when...

[release/6.0-staging] dotnet.exe prints error messages to console when launched with empty DOTNET_MULTILEVEL_LOOKUP (#88664)

src/installer/tests/HostActivation.Tests/PortableAppActivation.cs

@@ -322,7 +322,8 @@ public void AppHost_FrameworkDependent_GlobalLocation_Succeeds(bool useRegistere
                     .Execute()
                     .Should().Pass()
                     .And.HaveStdOutContaining("Hello World")
-                    .And.HaveStdOutContaining(sharedTestState.RepoDirectories.MicrosoftNETCoreAppVersion);
+                    .And.HaveStdOutContaining(sharedTestState.RepoDirectories.MicrosoftNETCoreAppVersion)
+                    .And.NotHaveStdErr();
 
                 // Verify running from within the working directory
                 Command.Create(appExe)
@@ -336,7 +337,8 @@ public void AppHost_FrameworkDependent_GlobalLocation_Succeeds(bool useRegistere
                     .Execute()
                     .Should().Pass()
                     .And.HaveStdOutContaining("Hello World")
-                    .And.HaveStdOutContaining(sharedTestState.RepoDirectories.MicrosoftNETCoreAppVersion);
+                    .And.HaveStdOutContaining(sharedTestState.RepoDirectories.MicrosoftNETCoreAppVersion)
+                    .And.NotHaveStdErr();
             }
         }
 

src/installer/tests/HostActivation.Tests/StartupHooks.cs

@@ -179,7 +179,8 @@ public void Muxer_activation_of_Empty_StartupHook_Variable_Succeeds()
                 .CaptureStdErr()
                 .Execute()
                 .Should().Pass()
-                .And.HaveStdOutContaining("Hello World");
+                .And.HaveStdOutContaining("Hello World")
+                .And.NotHaveStdErr();
         }
 
         // Run the app with a startup hook assembly that depends on assemblies not on the TPA list

src/native/corehost/hostmisc/pal.windows.cpp

@@ -499,14 +499,18 @@ bool pal::getenv(const char_t* name, string_t* recv)
         auto err = GetLastError();
         if (err != ERROR_ENVVAR_NOT_FOUND)
         {
-            trace::error(_X("Failed to read environment variable [%s], HRESULT: 0x%X"), name, HRESULT_FROM_WIN32(GetLastError()));
+            trace::warning(_X("Failed to read environment variable [%s], HRESULT: 0x%X"), name, HRESULT_FROM_WIN32(err));
         }
         return false;
     }
     auto buf = new char_t[length];
     if (::GetEnvironmentVariableW(name, buf, length) == 0)
     {
-        trace::error(_X("Failed to read environment variable [%s], HRESULT: 0x%X"), name, HRESULT_FROM_WIN32(GetLastError()));
+        auto err = GetLastError();
+        if (err != ERROR_ENVVAR_NOT_FOUND)
+        {
+            trace::warning(_X("Failed to read environment variable [%s], HRESULT: 0x%X"), name, HRESULT_FROM_WIN32(err));
+        }
         return false;
     }