Show dedicated message for tools with no entrypoints

[charliermarsh]

Summary

Closes #4688.

Test Plan

❯ cargo run tool install ruff
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.14s
     Running `target/debug/uv tool install ruff`
warning: `uv tool install` is experimental and may change without warning.
Resolved 1 package in 136ms
Installed 1 package in 3ms
 + ruff==0.5.0
No entrypoints to install for tool `ruff`

[zanieb]

Should we... fail? I feel like it doesn't "mean" anything to install a tool with no entry points.

[charliermarsh]

I mildly prefer not failing.

[zanieb]

Separately, I just noticed your example: we should probably have a message for installation of Ruff's executable.

[zanieb]

If there are no provided executables or entry points.. what is installing a tool?

[charliermarsh]

Ruff is fixed in #4693.

[charliermarsh]

If there are no provided executables or entry points.. what is installing a tool?

It puts the tool in a dedicated environment on your machine. In theory you could run that environment if you wanted an isolated environment with the tool? I don't know the use-case but failing seems user-hostile. Anyway you can decide, I don't feel the need to keep discussing.

[charliermarsh]

One data point:

❯ pipx install requests
Note: Dependent package 'charset-normalizer' contains 1 apps
  - normalizer

No apps associated with package requests. Try again with '--include-deps' to include apps of dependent packages, which
are listed above. If you are attempting to install a library, pipx should not be used. Consider using pip or a similar
tool instead.

[charliermarsh]

That seems like two votes for erroring, so I'll do that.

[zanieb]

Thanks!

I think we can revisit later, but yeah right now the environments are intended not to be user-facing and I'd recommend some other command for the no-entrypoints use case.

[charliermarsh]

Yeah all good!