Extends https://github.com/astral-sh/uv/pull/4121
Part of #2607
Adds support for managed toolchain fetching to `uv venv`, e.g.
```
❯ cargo run -q -- venv --python 3.9.18 --preview -v
DEBUG Searching for Python 3.9.18 in search path or managed toolchains
DEBUG Searching for managed toolchains at `/Users/zb/Library/Application Support/uv/toolchains`
DEBUG Found CPython 3.12.3 at `/opt/homebrew/bin/python3` (search path)
DEBUG Found CPython 3.9.6 at `/usr/bin/python3` (search path)
DEBUG Found CPython 3.12.3 at `/opt/homebrew/bin/python3` (search path)
DEBUG Requested Python not found, checking for available download...
DEBUG Using registry request timeout of 30s
INFO Fetching requested toolchain...
DEBUG Downloading https://github.com/indygreg/python-build-standalone/releases/download/20240224/cpython-3.9.18%2B20240224-aarch64-apple-darwin-pgo%2Blto-full.tar.zst to temporary location /Users/zb/Library/Application Support/uv/toolchains/.tmpgohKwp
DEBUG Extracting cpython-3.9.18%2B20240224-aarch64-apple-darwin-pgo%2Blto-full.tar.zst
DEBUG Moving /Users/zb/Library/Application Support/uv/toolchains/.tmpgohKwp/python to /Users/zb/Library/Application Support/uv/toolchains/cpython-3.9.18-macos-aarch64-none
Using Python 3.9.18 interpreter at: /Users/zb/Library/Application Support/uv/toolchains/cpython-3.9.18-macos-aarch64-none/install/bin/python3
Creating virtualenv at: .venv
INFO Removing existing directory
Activate with: source .venv/bin/activate
```
The preview flag is required. The fetch is performed if we can't find an
interpreter that satisfies the request. Once fetched, the toolchain will
be available for later invocations that include the `--preview` flag.
There will be follow-ups to improve toolchain management in general,
there is still outstanding work from the initial implementation.
Drops `find_toolchain`, `find_best_toolchain`, etc. in favor of
`Toolchain::find_...`
We can change this in the future, but there should only be one "right"
way to do it not two redundant ways in the public interface.
Extends #4120
Part of #2607
There should be no behavior changes here. Restructures the discovery API
to be focused on a toolchain first perspective in preparation for
exposing a `find_or_fetch` method for toolchains in
https://github.com/astral-sh/uv/pull/4138.
Moves all of `uv-toolchain` into `uv-interpreter`. We may split these
out in the future, but the refactoring I want to do for interpreter
discovery is easier if I don't have to deal with entanglement. Includes
some restructuring of `uv-interpreter`.
Part of #2386
Previously, this would use the "system" temporary directory.
Because we rename the resulting directory to its final destination,
and because renaming is implemented via hardlinking, and because
hardlinking doesn't work across mount points, and because /tmp is
commonly on a different mount point than where `uv` is checked out,
we "fix" this by putting the temporary directory somewhere close to
the final destination of the fetched artifact.
There are alternatives we might consider pursuing. For example,
if the `rename` fails, then we should probably do a recursive
directory copy. But this is a quick fix for now and it also
consistent with colocation of other temporary directories in `uv`.
The main downside of this change is that if a user does ^C while
`uv-dev fetch-python` is running, then there is no mechanism for
cleaning up temporary directories.
## Summary
This PR adds basic struct definitions along with a "workspace" concept
for discovering settings. (The "workspace" terminology is used to match
Ruff; I did not invent it.)
A few notes:
- We discover any `pyproject.toml` or `uv.toml` file in any parent
directory of the current working directory. (We could adjust this to
look at the directories of the input files.)
- We don't actually do anything with the configuration yet; but those
PRs are large and I want this to be reviewed in isolation.
See https://github.com/astral-sh/uv/issues/2617
Note this also includes:
- #2918
- #2931 (pending)
A first step towards Python toolchain management in Rust.
First, we add a new crate to manage Python download metadata:
- Adds a new `uv-toolchain` crate
- Adds Rust structs for Python version download metadata
- Duplicates the script which downloads Python version metadata
- Adds a script to generate Rust code from the JSON metadata
- Adds a utility to download and extract the Python version
I explored some alternatives like a build script using things like
`serde` and `uneval` to automatically construct the code from our
structs but deemed it to heavy. Unlike Rye, I don't generate the Rust
directly from the web requests and have an intermediate JSON layer to
speed up iteration on the Rust types.
Next, we add add a `uv-dev` command `fetch-python` to download Python
versions per the bootstrapping script.
- Downloads a requested version or reads from `.python-versions`
- Extracts to `UV_BOOTSTRAP_DIR`
- Links executables for path extension
This command is not really intended to be user facing, but it's a good
PoC for the `uv-toolchain` API. Hash checking (via the sha256) isn't
implemented yet, we can do that in a follow-up.
Finally, we remove the `scripts/bootstrap` directory, update CI to use
the new command, and update the CONTRIBUTING docs.
<img width="1023" alt="Screenshot 2024-04-08 at 17 12 15"
src="https://github.com/astral-sh/uv/assets/2586601/57bd3cf1-7477-4bb8-a8e9-802a00d772cb">
konsti