Bundle Python Interpreter in virtual environments

[Turakar]

For system wide installations of applications build with uv, it would be nice to have an option to build an execution environment which is self contained and does not rely on the user's local files (~/.local/share/uv). My usecase for this would be an application that I want to install to a server for system-wide usage. At the moment, you can achieve this with the following commands (with some path adjustments):

uv venv --no-cache
uv pip install --no-cache -r requirements.lock
cp -r ~/.local/share/uv/python/cpython-3.12.5-linux-x86_64-gnu python
rm .venv/bin/python
ln -s python/bin/python3.12 .venv/bin/python

# To run the program
.venv/bin/python <your script.py>

I.e., you can replace the symlinked python interpreter by a bundled copy.

I am not entirely sure how this should be implemented. In a first simple step, one could add a --bundle-python flag to uv venv which copies the downloaded Python interpreter to, e.g., .venv/python and uses it instead of a path in ~/.local/share/uv.

However, you can take this idea further, up to a uv install command which would do something similar to make install.

[Turakar]

Ok, you can kinda do this already by passing UV_PYTHON_INSTALL_DIR (docs) to uv venv.

[zanieb]

I think we want to add this feature.

[zanieb]

Related

• [Feature Request] allow exporting virtual environments #6970

[danielgafni]

Ohh til UV_PYTHON_INSTALL_DIR exists.

I was looking for this parameter in CLI --help and it's not mentioned there.

Perhaps

1. The env var should be mentioned in uv python * docs
2. uv python install * commands should take an --install-dir argument?

[zanieb]

Yes we should mention it in the help documentation. I'd also be down to accept a target directory in the CLI.

[danielgafni]

Ok, I started working on this in #7920. Does --install-dir name work?

[alexwilson1]

Bundling Python into .venv using UV_PYTHON_INSTALL_DIR does not work because when .venv is not empty (contains Python) the installation gives this error:

error: Project virtual environment directory cannot be used because it is not a compatible environment but cannot be recreated because it is not a virtual environment

--bundle-python would be ideal

[ginkgo97]

Will the option --install-dir or the env UV_PYTHON_INSTALL_DIR be able to be configured in uv.toml?