I'd love to be able to do mach try again --env FOO=1, and have FOO be added to the run environment.

I'm thinking about building treatment/no-treatment performance tests via environment variables.

This is a good idea, and I don't think it would be too difficult. This bug should be generalized to all try_configs and not just --env (e.g --artifact, --rebuild, etc).

If anyone wants to try and take a stab at it, you'll need to:

1. Add the try_configs here. See the fuzzy selector for an example.

2. Add the try_config parameter to the run function (copy fuzzy again).

3. Update the try_task_config pulled from history with these values.

You can test by making a try push (with chooser or fuzzy) and then running ./mach try again --no-push with various arguments, and inspecting the generated try_task_config.json to make sure the relevant options were added.