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)
## Summary
If the user puts their configuration in a `pyproject.toml` that _isn't_
a valid workspace root (e.g., it's a Poetry file), we won't discover it,
because we only look in `uv.toml` files in that case. I think this is
somewhat debatable... We could choose to _require_ `uv.toml` there, but
as a user I'd probably expect it to work?
Closes https://github.com/astral-sh/uv/issues/4521.
## Summary
In a workspace, we now read configuration from the workspace root.
Previously, we read configuration from the first `pyproject.toml` or
`uv.toml` file in path -- but in a workspace, that would often be the
_project_ rather than the workspace configuration.
We need to read configuration from the workspace root, rather than its
members, because we lock the workspace globally, so all configuration
applies to the workspace globally.
As part of this change, the `uv-workspace` crate has been renamed to
`uv-settings` and its purpose has been narrowed significantly (it no
longer discovers a workspace; instead, it just reads the settings from a
directory).
If a user has a `uv.toml` in their directory or in a parent directory
but is _not_ in a workspace, we will still respect that use-case as
before.
Closes#4249.
Zanie Blue