We have issues labeled as Good First Issue and Help Wanted which are good opportunities for new contributors.
Rust, a C compiler, and CMake are required to build uv.
On Ubuntu and other Debian-based distributions, you can install the C compiler and CMake with
sudo apt install build-essential cmake
CMake may be installed with Homebrew:
brew install cmake
The Python bootstrapping script requires coreutils
and zstd
; we recommend installing them with Homebrew:
brew install coreutils zstd
See the Python section for instructions on installing the Python versions.
You can install CMake from the installers or with pipx install cmake
(make sure that the pipx install path is in PATH
, pipx complains if it isn't).
For running tests, we recommend nextest.
Testing uv requires multiple specific Python versions. You can install them into
<project root>/bin
via our bootstrapping script:
pipx run scripts/bootstrap/install.py
Alternatively, you can install zstandard
from PyPI, then run:
python3.12 scripts/bootstrap/install.py
You can configure the bootstrapping directory with UV_BOOTSTRAP_DIR
.
You can invoke your development version of uv with cargo run -- <args>
. For example:
cargo run -- venv
cargo run -- pip install requests
Source distributions can run arbitrary code on build and can make unwanted modifications to your system ("Someone's Been Messing With My Subnormals!" on Blogspot, "nvidia-pyindex" on PyPI), which can even occur when just resolving requirements. To prevent this, there's a Docker container you can run commands in:
docker buildx build -t uv-builder -f builder.dockerfile --load .
# Build for musl to avoid glibc errors, might not be required with your OS version
cargo build --target x86_64-unknown-linux-musl --profile profiling --features vendored-openssl
docker run --rm -it -v $(pwd):/app uv-builder /app/target/x86_64-unknown-linux-musl/profiling/uv-dev resolve-many --cache-dir /app/cache-docker /app/scripts/popular_packages/pypi_10k_most_dependents.txt
We recommend using this container if you don't trust the dependency tree of the package(s) you are trying to resolve or install.
Please refer to Ruff's Profiling Guide, it applies to uv, too.
We provide diverse sets of requirements for testing and benchmarking the resolver in scripts/requirements
and for the installer in scripts/requirements/compiled
.
You can use scripts/bench
to benchmark predefined workloads between uv versions and with other tools, e.g.
python -m scripts.bench \
--uv-path ./target/release/before \
--uv-path ./target/release/after \
./scripts/requirements/jupyter.in --benchmark resolve-cold --min-runs 20
You can use tracing-durations-export to visualize parallel requests and find any spots where uv is CPU-bound. Example usage, with uv
and uv-dev
respectively:
RUST_LOG=uv=info TRACING_DURATIONS_FILE=target/traces/jupyter.ndjson cargo run --features tracing-durations-export --profile profiling -- pip compile scripts/requirements/jupyter.in
RUST_LOG=uv=info TRACING_DURATIONS_FILE=target/traces/jupyter.ndjson cargo run --features tracing-durations-export --bin uv-dev --profile profiling -- resolve jupyter
You can enable trace
level logging using the RUST_LOG
environment variable, i.e.
RUST_LOG=trace uv …
Releases can only be performed by Astral team members.
Changelog entries and version bumps are automated. First, run:
./scripts/release/bump.sh
Then, editorialize the CHANGELOG.md
file to ensure entries are consistently styled.
Then, open a pull request e.g. Bump version to ...
.
Binary builds will automatically be tested for the release.
After merging the pull request, run the release workflow
with the version tag. Do not include a leading v
.
The release will automatically be created on GitHub after everything else publishes.