pw_env_setup: Don't set project root var

Change-Id: I18f7e145455adbd4a6386926599c4599030ca6e9
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/51740
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Reviewed-by: Keir Mierle <keir@google.com>
diff --git a/pw_env_setup/py/pw_env_setup/env_setup.py b/pw_env_setup/py/pw_env_setup/env_setup.py
index adf9cde..a4828b0 100755
--- a/pw_env_setup/py/pw_env_setup/env_setup.py
+++ b/pw_env_setup/py/pw_env_setup/env_setup.py
@@ -214,8 +214,8 @@
         self._use_existing_cipd = use_existing_cipd
         self._virtualenv_gn_out_dir = virtualenv_gn_out_dir
 
-        if self._root_variable:
-            self._env.set(self._root_variable, project_root)
+        # if self._root_variable:
+        #     self._env.set(self._root_variable, project_root)
         self._env.set('PW_PROJECT_ROOT', project_root)
         self._env.set('PW_ROOT', pw_root)
         self._env.set('_PW_ACTUAL_ENVIRONMENT_ROOT', install_dir)