Resolve#6152
## Summary
## Test Plan
Execution result of `cargo run generate-shell-completion --help`
```bash
Generate shell completion
Usage: uv generate-shell-completion <SHELL>
Arguments:
<SHELL> The shell to generate the completion script for [possible values: bash, elvish, fish, nushell, powershell, zsh]
```
Execution result of `cargo run help generate-shell-completion`
```bash
Generate shell completion
Usage: uv generate-shell-completion <SHELL>
Arguments:
<SHELL>
The shell to generate the completion script for
[possible values: bash, elvish, fish, nushell, powershell, zsh]
```
## Summary
Resolves https://github.com/astral-sh/uv/issues/4537
- First commit avoids overwriting dependencies with different markers.
- Second commit supports adding from requirements files.
## Test Plan
`cargo test`
## Summary
This PR adds descriptions for the `UV_TOOL_DIR`, `UV_PYTHON_INSTALL_DIR`
and `XDG_*` environment variables.
Additionally, it moves some env vars that are not command-line arguments
to the below "uv respects" section.
Closes#5746
## Summary
`mkdocs` supports [validation rules for
links](https://www.mkdocs.org/user-guide/configuration/#validation),
which can be tightened to report more issues than the default
configuration. I used the recommended "maximal strictness" configuration
from the documentation.
Adding the `anchors` rule helped spot 4 errors:
```console
WARNING - Doc file 'guides/install-python.md' contains a link '../concepts/python-versions.md#python-distributions', but the doc 'concepts/python-versions.md' does not contain an anchor '#python-distributions'.
WARNING - Doc file 'guides/install-python.md' contains a link '../concepts/python-versions.md#discovery-order', but the doc 'concepts/python-versions.md' does not contain an anchor '#discovery-order'.
WARNING - Doc file 'guides/projects.md' contains a link '../concepts/projects.md#lock-file', but the doc 'concepts/projects.md' does not contain an anchor '#lock-file'.
WARNING - Doc file 'pip/environments.md' contains a link '../concepts/python-versions.md#discovery-order', but the doc 'concepts/python-versions.md' does not contain an anchor '#discovery-order'.
```
## Test Plan
Local run of the documentation + `mkdocs build --strict`.
## Summary
We now persist the `ResolverInstallerOptions` when writing out a tool
receipt. When upgrading, we grab the saved options, and merge with the
command-line arguments and user-level filesystem settings (CLI > receipt
> filesystem).
The loose consensus is that "fetch" doesn't have much meaning and that a
boolean flag makes more sense from the command line.
1. Adds `--allow-python-downloads` (hidden, default) and
`--no-python-downloads` to the CLI to quickly enable or disable
downloads
2. Deprecates `--python-fetch` in favor of the options from (1)
3. Removes `python-fetch` in favor of a `python-downloads` setting
5. Adds a `never` variant to the enum, allowing even explicit installs
to be disabled via the configuration file
## Test plan
I tested this with various `pyproject.toml`-level settings and `uv venv
--preview --python 3.12.2` and `uv python install 3.12.2` with and
without the new CLI flags.
## Summary
I think this seems reasonable... Otherwise, we might not go back to PyPI
to revalidate the list of available versions despite the user passing
`--upgrade`.
## Summary
Previously, we wouldn't respect configuration files in directories
_above_ a workspace root. But this is somewhat problematic, because any
`pyproject.toml` will define a workspace root...
Instead, I think we should _start_ the search at the workspace root, but
go above it if necessary.
Closes: #5929.
See: https://github.com/astral-sh/uv/pull/4295.
## Summary
Resolves#5188. Most of the changes involve creating a new function in
`tool/common.rs` to contain the common functionality previously found in
`tool/install.rs`.
## Test Plan
`cargo test`
```console
❯ ./target/debug/uv tool upgrade black
warning: `uv tool upgrade` is experimental and may change without warning.
Resolved 6 packages in 25ms
Uninstalled 1 package in 3ms
Installed 1 package in 19ms
- black==23.1.0
+ black==24.4.2
Installed 2 executables: black, blackd
```
Following #5869, the documentation has some less-than-helpful
suggestions to use `uv help python` for details — we should link to the
`uv python` section instead.
