## Summary
We use a similar strategy to the ephemeral overlay: set
`include-system-site-packages` in the `pyvenv.cfg`, and clear it
whenever we access a new environment.
Closes https://github.com/astral-sh/uv/issues/11829.
## Test Plan
Difficult to test because we don't really have support for system
packages in our test infrastructure. But...
```
> uv venv --system-site-packages
> ['', '/Users/crmarsh/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/lib/python313.zip', '/Users/crmarsh/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/lib/python3.13', '/Users/crmarsh/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/lib/python3.13/lib-dynload', '/Users/crmarsh/.cache/uv/archive-v0/AhKcORkaCdbBl31VweRtG/lib/python3.13/site-packages', '/Users/crmarsh/workspace/uv/foo/.venv/lib/python3.13/site-packages', '/Users/crmarsh/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/lib/python3.13/site-packages']
```
```
> uv venv
> ['', '/Users/crmarsh/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/lib/python313.zip', '/Users/crmarsh/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/lib/python3.13', '/Users/crmarsh/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/lib/python3.13/lib-dynload', '/Users/crmarsh/.cache/uv/archive-v0/AhKcORkaCdbBl31VweRtG/lib/python3.13/site-packages', '/Users/crmarsh/workspace/uv/foo/.venv/lib/python3.13/site-packages']
```
## Summary
I'm not sure that this has much of an effect in practice, but currently,
when we return a virtual environment, the `sys_base_executable ` of the
parent ends up being retained as `sys_base_executable` of the created
environment. But these can be, like, subtly different? If you have a
symlink to a Python, then for the symlink, `sys_base_executable` will be
equal to `sys_executable`. But when you create a virtual environment for
that interpreter, we'll set `home` to the resolved symlink, and so
`sys_base_executable` will be the resolved symlink too, in general.
Anyway, this means that we should now have a consistent value between
(1) returning `Virtualenv` from the creation routine and (2) querying
the created interpreter.
## Summary
This PR declares and documents all environment variables that are used
in one way or another in `uv`, either internally, or externally, or
transitively under a common struct.
I think over time as uv has grown there's been many environment
variables introduced. Its harder to know which ones exists, which ones
are missing, what they're used for, or where are they used across the
code. The docs only documents a handful of them, for others you'd have
to dive into the code and inspect across crates to know which crates
they're used on or where they're relevant.
This PR is a starting attempt to unify them, make it easier to discover
which ones we have, and maybe unlock future posibilities in automating
generating documentation for them.
I think we can split out into multiple structs later to better organize,
but given the high influx of PR's and possibly new environment variables
introduced/re-used, it would be hard to try to organize them all now
into their proper namespaced struct while this is all happening given
merge conflicts and/or keeping up to date.
I don't think this has any impact on performance as they all should
still be inlined, although it may affect local build times on changes to
the environment vars as more crates would likely need a rebuild. Lastly,
some of them are declared but not used in the code, for example those in
`build.rs`. I left them declared because I still think it's useful to at
least have a reference.
Did I miss any? Are their initial docs cohesive?
Note, `uv-static` is a terrible name for a new crate, thoughts? Others
considered `uv-vars`, `uv-consts`.
## Test Plan
Existing tests
## 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)
Charlie Marsh
Ed Morley
konsti
Zanie Blue
samypr100
Pavel Dikov