What is a generation?

Generations refer to a version number of an environment on FloxHub. Both imperative and declarative commands that modify an environment on FloxHub increment the generation number for the environment.

Read more about creating your first generation in the sharing guide.

First generation

The first environment generation (1) is created when you use flox push to send an environment to FloxHub.

New generations

New generations are created automatically when you use a CLI command that modifies the environment, such as flox install or flox edit.

Staged local generations

With a centrally managed environment new local generations are staged automatically. Suppose you flox pull an environment at generation 15 on FloxHub. If you now run flox install three times then you will have generations 16-18 locally. The next flox push would sync these three new generations to FloxHub if you have permission to write to the environment.

Switching and viewing generations

Generations offer change management for environments; it's similar to git, but tailored for environments.

Suppose you make an edit to an environment, but then after activating and using the environment, you want to undo the change you just made. To undo the change, you can run flox generations rollback.

If you've made a series of edits over time but later realize you want to discard them all, you can use flox generations list to display all the different versions of the environment, and then you can use flox generations switch <generation number> to revert to the version of the environment prior to all the environments. You can also view generations on FloxHub on the Generations tab of an environment's page.

History

Rolling back to a previous generation introduces another concept: history. Rolling back doesn't create a new generation, but it does add an entry to the environment's history. Suppose you flox generations rollback from generation 18 to 17. Although the list of generations hasn't changed, the latest entry in the environment's history will now say that generation 17 is the current generation. Note that although generation 18 is the "latest" in the sense that it has the highest generation number and was most recently created, it is not the latest to be current.

This history of what generation is current at a given point in time can be viewed on FloxHub on the Change Log tab for an environment. Or, to use the CLI to view history, you can run flox generations history. This provides a log of what generation of an environment was current at the time an environment was activated remotely without being pulled, with flox activate -r.

Generation lock

Centrally managed environments that are pulled with flox pull will store a generation lock which describes the current pulled generation. This allows this environment to advance to newer generations explicitly on the next flox pull.