Build From Source

We recommend building EnvPool on Ubuntu 22.04 environment.

We use bazel to build EnvPool. Comparing with pip, using Bazel to build python package with C++ .so files has some advantages:

  • Bazel allows us to build from source code, but no need to directly includes the code in our repo;

  • no need to write complex CMake files, especially with multiple third-party dependencies;

  • using Bazel for CI test pipeline can only run the test with modified part, so that it can save a lot of time.

Install Bazelisk

Bazelisk is a version controller for Bazel. You can install it via npm

sudo apt install -y npm
npm install -g @bazel/bazelisk

or golang with version >= 1.16:

sudo apt install -y golang
export PATH=$HOME/go/bin:$PATH
go install
ln -sf $HOME/go/bin/bazelisk $HOME/go/bin/bazel


For users in mainland China, please do the following step to install go and bazel:

  1. Install golang >= 1.16 from other sites, e.g.,

  2. Change go proxy: go env -w GOPROXY=

  3. Install bazel from

# then follow the instructions on golang official website
go env -w GOPROXY=

chmod +x bazel-6.0.0-linux-x86_64
mkdir -p $HOME/go/bin
mv bazel-6.0.0-linux-x86_64 $HOME/go/bin/bazel

export PATH=$PATH:$HOME/go/bin  # or write to .bashrc / .zshrc

# check if successfully installed

See Issue #87.

Install Other Dependencies

EnvPool requires GCC/G++ version >= 9.0 to build the source code. To install:

# optional
sudo add-apt-repository ppa:ubuntu-toolchain-r/test

# install
sudo apt install -y gcc-9 g++-9 build-essential

# to change the default cc to gcc-9:
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 60 --slave /usr/bin/g++ g++ /usr/bin/g++-9

It also requires Python version >= 3.7:

sudo apt install -y python3-dev python3-pip
sudo ln -sf /usr/bin/python3 /usr/bin/python

Install CUDA to enable XLA: see

Install other dependencies: see Dockerfile.

Build Wheel

To build a release version, type:

cp third_party/pip_requirements/requirements-release.txt third_party/pip_requirements/requirements.txt
bazel run --config=release //:setup -- bdist_wheel

This creates a wheel under bazel-bin/setup.runfiles/envpool/dist.


For users in mainland China:

  • If you find pip install is quite slow to fetch 3rd-party libraries, the solution is to uncomment extra_args in envpool/pip.bzl to switch the pip source.

  • If you find bazel build is quite slow to fetch 3rd-party libraries, please refer

    export HTTP_PROXY=http://...
    export HTTPS_PROXY=http://...
    # then run the command to build

See Issue #87.

Use Shortcut

We provide several shortcuts to make things easier.

# This will install bazelisk via golang, need sudo
make bazel-install

# This will verbose all compile commands to help debug
make bazel-debug

# This will build python wheel (.whl) file under `dist/` folder
make bazel-build

# This will automatically run the tests
make bazel-test

# This will build a wheel for release
make bazel-release

Use Docker to Create Develop Environment

We also provide dockerfile for building such a container. To create a docker develop environment, run

make docker-dev

The code is under /app, and you can communicate with the host machine file system via /host.


For users in mainland China:

make docker-dev-cn

See Issue #87.