uv/docs/concepts
Charlie Marsh e4fc875afa
Allow conflicting extras in explicit index assignments (#9160)
## Summary

This PR enables something like the "final boss" of PyTorch setups --
explicit support for CPU vs. GPU-enabled variants via extras:

```toml
[project]
name = "project"
version = "0.1.0"
requires-python = ">=3.13.0"
dependencies = []

[project.optional-dependencies]
cpu = [
    "torch==2.5.1+cpu",
]
gpu = [
    "torch==2.5.1",
]

[tool.uv.sources]
torch = [
    { index = "torch-cpu", extra = "cpu" },
    { index = "torch-gpu", extra = "gpu" },
]

[[tool.uv.index]]
name = "torch-cpu"
url = "https://download.pytorch.org/whl/cpu"
explicit = true

[[tool.uv.index]]
name = "torch-gpu"
url = "https://download.pytorch.org/whl/cu124"
explicit = true

[tool.uv]
conflicts = [
    [
        { extra = "cpu" },
        { extra = "gpu" },
    ],
]
```

It builds atop the conflicting extras work to allow sources to be marked
as specific to a dedicated extra being enabled or disabled.

As part of this work, sources now have an `extra` field. If a source has
an `extra`, it means that the source is only applied to the requirement
when defined within that optional group. For example, `{ index =
"torch-cpu", extra = "cpu" }` above only applies to
`"torch==2.5.1+cpu"`.

The `extra` field does _not_ mean that the source is "enabled" when the
extra is activated. For example, this wouldn't work:

```toml
[project]
name = "project"
version = "0.1.0"
requires-python = ">=3.13.0"
dependencies = ["torch"]

[tool.uv.sources]
torch = [
    { index = "torch-cpu", extra = "cpu" },
    { index = "torch-gpu", extra = "gpu" },
]

[[tool.uv.index]]
name = "torch-cpu"
url = "https://download.pytorch.org/whl/cpu"
explicit = true

[[tool.uv.index]]
name = "torch-gpu"
url = "https://download.pytorch.org/whl/cu124"
explicit = true
```

In this case, the sources would effectively be ignored. Extras are
really confusing... but I think this is correct? We don't want enabling
or disabling extras to affect resolution information that's _outside_ of
the relevant optional group.
2024-11-19 01:06:25 +00:00
..
cache.md Fix cache-keys typo in tags = true (#8422) 2024-10-21 17:35:22 +00:00
dependencies.md Allow conflicting extras in explicit index assignments (#9160) 2024-11-19 01:06:25 +00:00
index.md Update documentation sections (#5452) 2024-07-25 12:37:22 -05:00
projects.md docs: add some words about specifying conflicting extras/groups (#9120) 2024-11-14 13:50:18 -06:00
python-versions.md Add project boundary note (#8900) 2024-11-07 15:49:14 -06:00
resolution.md Fix reference to --resolution in docs (#8968) 2024-11-09 13:43:53 +00:00
tools.md docs: add missing console highlights (#6900) 2024-08-31 19:04:19 -04:00
workspaces.md Update workspace documentation to remove legacy virtual projects (#6720) 2024-08-27 17:31:12 -04:00