# Description
Closes#7110. ~~Note that unlike "real" `mut` vars, $env can be deeply
mutated via stuff like `$env.PYTHON_IO_ENCODING = utf8` or
`$env.config.history.max_size = 2000`. So, it's a slightly awkward
special case, arguably justifiable because of what $env represents (the
environment variables of your system, which is essentially "outside"
normal Nushell regulations).~~
EDIT: Now allows all `mut` vars to be deeply mutated using `=`, on
request.
# User-Facing Changes
See above.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.