UX: `uv python install` silently skips requests depending on what I already have installed

[neutrinoceros]

Summary

Starting from a state where I don't have a managed copy of Python 3.14 installed. Installing works as expected

❯ uv python install 3.14
Installed Python 3.14.0a5 in 15.92s
 + cpython-3.14.0a5-macos-aarch64-none

However, immediately running the same command doesn't produce any output

❯ uv python install 3.14

this is surprising to me: I would expect a "warning" of some sort to tell me that I already have the requested version installed, which is why nothing was done.
Even in verbose mode, there doesn't seem to be a clear indication of that skip

❯ uv python install 3.14 -v
DEBUG uv 0.6.0 (591f38c25 2025-02-14)
DEBUG Acquired lock for `/Users/clm/.local/share/uv/python`
DEBUG Found `cpython-3.14.0a5-macos-aarch64-none` for request `Python 3.14`
DEBUG Using request timeout of 30s
DEBUG Skipping installation of Python executables, use `--preview` to enable.
DEBUG Released lock at `/Users/clm/.local/share/uv/python/.lock`

Of course in the context of this minimal reprod it is pretty obvious what's happening, but it's a little bit more confusing when running a longer command such as, e.g.

❯ uv python install 3.14 3.13 3.12 3.11

and all versions I requested but one appear on the output.

update: this second part was resolved in #12124
I'm putting it in quote mode to highlight this fact

Similarily, if I try to re-install a version I don't already have, it is also silently skipped

❯ uv python install 3.14t --reinstall

This time, in verbose mode, the version I asked for is not even mentioned

❯ uv python install 3.14t --reinstall -v
DEBUG uv 0.6.0 (591f38c25 2025-02-14)
DEBUG Acquired lock for `/Users/clm/.local/share/uv/python`
DEBUG Using request timeout of 30s
DEBUG Released lock at `/Users/clm/.local/share/uv/python/.lock`

Platform

Darwin 24.3.0 arm64

Version

uv 0.6.0 (591f38c 2025-02-14)

Python version

Python 3.13.2

[zanieb]

Seems like we could do something better here

For reference, the output from, e.g., uv pip install, looks like

❯ uv pip install anyio
Resolved 3 packages in 77ms
Installed 3 packages in 7ms
 + anyio==4.8.0
 + idna==3.10
 + sniffio==1.3.1
❯ uv pip install anyio
Audited 1 package in 2ms

Also the log that your request is satisfied is

DEBUG Found cpython-3.14.0a5-macos-aarch64-none for request Python 3.14

[neutrinoceros]

Also the log that your request is satisfied is

Ah ! I wasn't sure if this line was about the requested interpreter found on my system or on the host server !

[zanieb]

Yeah the message for that is, e.g.

DEBUG Found download cpython-3.12.8-macos-aarch64-none for request Python 3.12.8

We can clear things up here though

[neutrinoceros]

#12124 was merged and looks to me like it partially address this issue.
@zanieb do you know if this should be closed ?

[neutrinoceros]

nevermind I just tried it again, and this part is sill relevant

this is surprising to me: I would expect a "warning" of some sort to tell me that I already have the requested version installed, which is why nothing was done.

I'll edit the OP to reflect that part of it is now solved though

[zanieb]

👍 I can work on the messaging still, just lots of tasks on the backlog :)

[neutrinoceros]

No rush at all. In fact, I'm game to give it a try myself.