--python can't be used when UV_SYSTEM_PYTHON=false

[thejcannon]

👋 I think this is a CLI quirk, but both of this errors for me:

$ UV_SYSTEM_PYTHON=false uv pip install --python .venv/bin/python```

(Our use case is that by default CI uses `UV_SYSTEM_PYTHON` but in certain tests it uses `uv` to make dedicated venvs for the test)

[thejcannon]

(I assume this is a quirk of the group:

uv/crates/uv/src/cli.rs

Line 776 in ce4d862

group = "discovery"

)

[charliermarsh]

Yes there's no way to support this in Clap. We'd have to remove the group IIRC.

[thejcannon]

Also note that uv pip install --python .venv/bin/python --no-system works.

Also just scrubbing the env before calling uv works.

[zanieb]

Ah I recently ran into this at tox-dev/tox-uv#57 (comment) too

It would be nice to override it...

[thejcannon]

@epage 👋 Do you think this is something Clap would reasonably support (some kind of "its only a collision if two in the group are "truthy"")? If not, @charliermarsh you can probably just close this issue as not planned. There's an easy workaround.

(I couldn't tell if this fit in any of the existing issues, like clap-rs/clap#5041 or if multiple plus manual validation was the way to go)

[charliermarsh]

We ran into it before and I think we ended up removing the group.

[charliermarsh]

Actually confused because I thought I fixed this in #3000.

[charliermarsh]

(But clearly I didn't.)

[charliermarsh]

I'll just remove the group for now. Better experience.

[thejcannon]

Oh, well also I should point out uv --version gives me uv 0.1.44 (d417daad7 2024-05-14)

[zanieb]

Weird...

❯ uv self update
info: Checking for updates...
success: Upgraded `uv` to v0.2.3! https://github.com/astral-sh/uv/releases/tag/0.2.3
❯ which uv
/Users/zb/.cargo/bin/uv
❯ uv --version
uv 0.2.3 (ce4d862b0 2024-05-24)
❯ uv venv
Using Python 3.12.3 interpreter at: /opt/homebrew/opt/python@3.12/bin/python3.12
Creating virtualenv at: .venv
Activate with: source .venv/bin/activate
❯ uv pip install uv
Resolved 1 package in 151ms
Downloaded 1 package in 1.00s
Installed 1 package in 6ms
 + uv==0.2.3
❯ .venv/bin/uv --version
uv 0.2.3 (ce4d862b0 2024-05-24)

edit: Oh, you mean you're actually on an older version :D

[zanieb]

Definitely not fixed on the latest version though

❯ UV_SYSTEM_PYTHON=1 uv pip install --python .venv anyio
error: the argument '--python <PYTHON>' cannot be used with '--system'

Usage: uv pip install --python <PYTHON> <PACKAGE|--requirement <REQUIREMENT>|--editable <EDITABLE>|--unstable-uv-lock-file <UNSTABLE_UV_LOCK_FILE>>

For more information, try '--help'.

[thejcannon]

Yeah I just wanted to get ahead of "oh maybe Josh is using an older version 😂 "

(I should type more words in my comments 🤔 )

[epage]

For context, clap doesn't consider there to be a conflict for default values, only explicit user values. Environment variables are a weird middle ground that we currently treat as user values which cause problems like this.