Dotenv and production

Quick question about env variables defined for multiple environments. Say I have a .env file for use locally but when publishing to production need to use the definitions for the remote environment. I'm using the dotenv crate (which appears to have some crisis of identity since the source repo is empty). If running dotenv::dotenv() returns an Error due to lack of a .env file, std::env::var() fall back to production environment definitions?

Have you tried it out locally? Rename your .env file, and add all the included variables to your environment (export VAR=value in bash and other bourne-descended shells).