We've been working hard to solidify Compose's environment variable support.

Countless quirks, edge cases, and bugs have been addressed across the past several releases.

As part of this, we're still putting the finishing touches on updated documentation! It's been a big effort and we've discovered parts of the Compose specification that were underspecified or incorrect.

We know it can be frustrating to need to make adjustments as a result, but we're confident we're building a more predictable and standards-driven foundation for Compose moving forward.

💁‍♀️ If you are relying on advanced environment variable features, such as parameter expansion in .env files, we recommend upgrading to v2.11.2+!

VIEW DOCS @ https://docs.docker.com/compose/env-file/