I think this would give us better hygiene than a global flag. It makes
it easier for users to opt-in to overlapping features, such as Python
upgrades and Python bin installations and to disable warnings for
preview mode without opting in to a bunch of other features. In general,
I want to reduce the burden for putting something under preview.
The `--preview` and `--no-preview` flags are retained as global
overrides. A new `--preview-features` option is added which accepts
comma separated features or can be passed multiple times, e.g.,
`--preview-features add-bounds,pylock`. There's a `UV_PREVIEW_FEATURES`
environment variable for that option (I'm not sure if we should overload
`UV_PREVIEW`, but could be convinced).
## Summary
If `HF_TOKEN` is set, we'll automatically wire it up to authenticate
requests when hitting private `huggingface.co` URLs in `uv run`.
## Test Plan
An unauthenticated request:
```
> cargo run -- run https://huggingface.co/datasets/cmarsh/test/resolve/main/main.py
File "/var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/mainYadr5M.py", line 1
Invalid username or password.
^^^^^^^^
SyntaxError: invalid syntax
```
An authenticated request:
```
> HF_TOKEN=hf_... cargo run run https://huggingface.co/datasets/cmarsh/test/resolve/main/main.py
Hello from main.py!
```
By default, `uv venv <venv-name>` currently removes the `<venv-name`>
directory if it exists. This can be surprising behavior: not everyone
expects an existing environment to be overwritten. This PR updates the
default to fail if a non-empty `<venv-name>` directory already exists
and neither `--allow-existing` nor the new `-c/--clear` option is
provided (if a TTY is detected, it prompts first). If it's not a TTY,
then uv will only warn and not fail for now — we'll make this an error
in the future. I've also added a corresponding `UV_VENV_CLEAR` env var.
I've chosen to use `--clear` instead of `--force` for this option
because it is used by the `venv` module and `virtualenv` and will be
familiar to users. I also think its meaning is clearer in this context
than `--force` (which could plausibly mean force overwrite just the
virtual environment files, which is what our current `--allow-existing`
option does).
Closes#1472.
---------
Co-authored-by: Zanie Blue <contact@zanie.dev>
Adds environment variables for
https://github.com/astral-sh/uv/pull/14612 and
https://github.com/astral-sh/uv/pull/14614
We can't use the Clap `BoolishValueParser` here, and the reasoning is a
little hard to explain. If we used `UV_PYTHON_INSTALL_NO_BIN`, as is our
typical pattern, it'd work, but here we allow opt-in to hard errors with
`UV_PYTHON_INSTALL_BIN=1` and I don't think we should have both
`UV_PYTHON_INSTALL_BIN` and `UV_PYTHON_INSTALL_NO_BIN`.
Consequently, this pull request introduces a new `EnvironmentOptions`
abstraction which allows us to express semantics that Clap cannot —
which we probably want anyway because we have an increasing number of
environment variables we're parsing downstream, e.g., #14544 and #14369.
## Summary
When installing packages on _very_ slow/overloaded systems it'spossible
to trigger bytecode compilation timeouts, which tends to happen in
environments such as Qemu (especially without KVM/virtio), but also on
systems that are simply overloaded. I've seen this in my Nix builds if I
for example am compiling a Linux kernel at the same time as a few other
concurrent builds.
By making the bytecode compilation timeout adjustable you can work
around such issues. I plan to set `UV_COMPILE_BYTECODE_TIMEOUT=0` in the
[pyproject.nix
builders](https://pyproject-nix.github.io/pyproject.nix/build.html) to
make them more reliable.
- Related issues
* https://github.com/astral-sh/uv/issues/6105
## Test Plan
Only manual testing was applied in this instance. There is no existing
automated tests for bytecode compilation timeout afaict.
Closes#14262
## Description
Adds `UV_LIBC` environment variable and implements check within
`Libc::from_env` as recommended here:
https://github.com/astral-sh/uv/issues/14262#issuecomment-3014600313
Gave this a few passes to make sure I follow dev practices within uv as
best I am able. Feel free to call out anything that could be improved.
## Test Plan
Planned to simply run existing test suite. Open to adding more tests
once implementation is validated due to my limited Rust experience.
Extends https://github.com/astral-sh/uv/pull/13841 — I'll drop that
commit later after that pull request merges but it's small.
I find the split into a "Configuration" section awkward and don't think
it's helping us. Everything moved into the "Concepts" section, except
the "Environment variables" page which definitely belongs in the
reference and the "Installer" page which is fairly niche and seems
better in the reference.
Before / After
<img
src="https://github.com/user-attachments/assets/80d8304b-17da-4900-a5f4-c3ccac96fcc5"
width="400">
2025-06-05 17:09:49 +00:00
Renamed from docs/configuration/environment.md (Browse further)
