This PR adds support for upgrading the build environment of tools with
the addition of a ```--python``` argument to ```uv upgrade```, as
specified in #7471.
Some things to note:
- I added support for individual packages — I didn't think there was a
good reason for ```--python``` to only apply to all packages
- Upgrading with ```--python``` also upgrades the package itself — I
think this is fair as if a user wants to _strictly_ switch the version
of Python being used to build a tool's environment they can use ```uv
install```. This behavior can of course be modified if others don't
agree!
Closes https://github.com/astral-sh/uv/issues/6297.
Closes https://github.com/astral-sh/uv/issues/7471.
As we support more complex Python discovery behaviors such as:
- #7431
- #7335
- #7300
`Any` is no longer accurate, we actually are looking for a reasonable
default Python version to use which may exclude the first one we find.
Separately, we need the idea of `Any` to improve behavior when listing
versions (e.g., #7286) where we do actually want to match _any_ Python
version. As a first step, we'll rename `Any` to `Default`. Then, we'll
introduce a new `Any` that actually behaves as we'd expect.
## Summary
Adds a `--relocatable` CLI arg to `uv venv`. This flag does two things:
* ensures that the associated activation scripts do not rely on a
hardcoded
absolute path to the virtual environment (to the extent possible; `.csh`
and
`.nu` left as-is)
* persists a `relocatable` flag in `pyvenv.cfg`.
The flag in `pyvenv.cfg` in turn instructs the wheel `Installer` to
create script
entrypoints in a relocatable way (use `exec` trick + `dirname $0` on
POSIX;
use relative path to `python[w].exe` on Windows).
Fixes: #3863
## Test Plan
* Relocatable console scripts covered as additional scenarios in
existing test cases.
* Integration testing of boilerplate generation in `venv`.
* Manual testing of `uv venv` with and without `--relocatable`
Whew this is a lot.
The user-facing changes are:
- `uv toolchain` to `uv python` e.g. `uv python find`, `uv python
install`, ...
- `UV_TOOLCHAIN_DIR` to` UV_PYTHON_INSTALL_DIR`
- `<UV_STATE_DIR>/toolchains` to `<UV_STATE_DIR>/python` (with
[automatic
migration](https://github.com/astral-sh/uv/pull/4735/files#r1663029330))
- User-facing messages no longer refer to toolchains, instead using
"Python", "Python versions" or "Python installations"
The internal changes are:
- `uv-toolchain` crate to `uv-python`
- `Toolchain` no longer referenced in type names
- Dropped unused `SystemPython` type (previously replaced)
- Clarified the type names for "managed Python installations"
- (more little things)