Support uv tool install package@version to match uvx

[zanieb]

Otherwise, going from uvx to uv tool install can be surprising.

[baggiponte]

I wonder whether using @ is appropriate over package==version. The @ is documented for example here for uv pip install "ruff @ ./projects/ruff".

[charliermarsh]

package==version does work here already. But uvx uses package@version because it does not accept an arbitrary version specifier, just a single version, and we want to disambiguate.

[chrisrodrigue]

@ is very commonly used for specifying locations/paths, for example person@company.com or package@path/to/pkg/src.

Maybe this could cause some confusion/surprises.

[zanieb]

It might not be worth it, but... I'm not sure if it's that common? We had a lot of complaints about requiring package @ path and I'm not sure how person@company applies? Regardless, we can easily:

1. Tell if it's a path and/or
2. Treat it as we would now if it's not a valid PEP 440 version — that's what we do in uvx tool@version

[chrisrodrigue]

Ah sorry, I should have clarified that person@company.com is an email address 😆

I’m not sure what PEPs might govern tokens used in the context of package paths/versions but RFC 3986 could be a good standard to reference that covers allowed uses of @ in URIs if there isn’t anything more relevant.

[zanieb]

To be clear — we already support uvx ruff@0.6.1 and uvx ruff@latest so we already have clear semantics around this. This issue is about extending those semantics to uv tool install to avoid confusion.

[chrisrodrigue]

That makes sense 😁

(By the way, it looks like PEP 440 covers @ for direct references with explicit URLs.)

[charliermarsh]

Gonna do this now.

[damienrj]

This would also make sense given the docs indicate that the @ is the method for doing the install.

The name of the command can include an exact version in the format @, e.g., uv run ruff@0.3.0. If more complex version specification is desired or if the command is provided by a different package, use --from.

[charliermarsh]

(Separately, there's a typo there, it should be uv tool run ruff@0.3.0.)