Revert "Guard nodenv-prefix call from 'system'"
Revert "Guard nodenv-prefix call from 'system'"

This reverts commit fac1d6db0b289bf99b1800ad30b26a12cd4bfb64.

jrolfs/nodenv,OiNutter/nodenv,jrolfs/nodenv,OiNutter/nodenv,nodenv/nodenv,nodenv/nodenv