use wd.SetReattachInfo

helper/resource/plugin.go

@@ -119,7 +119,7 @@ func runProviderCommand(t testing.T, f func() error, wd *tftest.WorkingDir, fact
 	if err != nil {
 		return err
 	}
-	wd.Setenv("TF_REATTACH_PROVIDERS", string(reattachStr))
+	wd.SetReattachInfo(string(reattachStr))
 
 	// ok, let's call whatever Terraform command the test was trying to
 	// call, now that we know it'll attach back to those servers we just
@@ -146,7 +146,7 @@ func runProviderCommand(t testing.T, f func() error, wd *tftest.WorkingDir, fact
 	// longer valid. In theory it should be overwritten in the next call,
 	// but just to avoid any confusing bug reports, let's just unset the
 	// environment variable altogether.
-	wd.Unsetenv("TF_REATTACH_PROVIDERS")
+	wd.UnsetReattachInfo()
 
 	// return any error returned from the orchestration code running
 	// Terraform commands