rosenv-setup

Stop manually sourcing ROS workspaces. One script sets everything up — then just cd and it works.

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The problem

Every ROS developer knows this pain:

# every. single. terminal.
source /opt/ros/jazzy/setup.bash # 
source ~/ros2_ws/install/local_setup.sh # cases when it's built from source

And when you have multiple workspaces across different distros, you either edit .bashrc back and forth or forget to source and spend ten minutes debugging why ros2 topic list isn't working.

The solution

This script sets up direnv to automatically source the correct ROS environment the moment you cd into a workspace — and unload it when you leave. No more manual sourcing. No global shell pollution. Each workspace is fully isolated.

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How it works

Setup (once):

ros_direnv_setup.sh
├── detects your shell (bash / zsh / fish)
├── detects your ROS installation (from env variables or asks you)
├── installs direnv if missing (or tells you how)
├── hooks direnv into your shell rc file
└── adds a ros-init function to your shell rc file

Per workspace (one command):

cd ~/your_ws
ros-init

After that, switching is just cd:

cd ~/ros2_jazzy     # → jazzy environment loads
cd ~/ros2_humble    # → switches to humble automatically
cd ~                # → ROS environment unloads cleanly

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Installation

git clone https://github.com/yourusername/ros-direnv-setup
cd ros-direnv-setup
chmod +x ros_direnv_setup.sh
./ros_direnv_setup.sh

The script will:

1. Detect your ROS setup.bash from $AMENT_PREFIX_PATH or $ROS_DISTRO automatically
2. Ask you for the path if it cannot find it
3. Verify every path exists before writing anything
4. Install direnv and wire everything into your shell rc file

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Requirements

Requirement	Notes
bash	The installer script runs with bash. Your daily shell can be anything — bash, zsh, or fish. Run it as bash ros_direnv_setup.sh, not sh.
ROS	Any distro, any installation method — apt, built from source, or custom path. ROS1 and ROS2 both work.
sudo access	Only needed if direnv is not yet installed.
direnv	Installed automatically by the script if missing. If auto-install fails, the script prints the manual install command for your OS.

Note on shells: The script itself must be run with bash (it uses bash-specific syntax). However it detects your current shell — bash, zsh, or fish — and writes the correct hook and ros-init syntax into the right rc file automatically.

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Shell support

Shell	rc file written to	Supported
bash	~/.bashrc	✓
zsh	~/.zshrc	✓
fish	~/.config/fish/config.fish	✓
other	prompts you for the rc file path	✓

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ROS compatibility

Installation type	Detected via	Supported
ROS2 apt install	$ROS_DISTRO	✓
ROS2 built from source	$AMENT_PREFIX_PATH	✓
ROS1 (noetic)	$ROS_DISTRO	✓
Custom path	manual prompt	✓

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After setup

For every new workspace you create:

cd ~/your_new_ws
ros-init

This drops a .envrc file into the workspace with your detected ROS paths, and trusts it with direnv. From that point on, the environment is managed automatically.

You can also commit .envrc to git — anyone on your team with direnv installed gets the same behaviour without any manual setup.

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Idempotent

Safe to run multiple times. The script checks before writing — if direnv or ros-init is already in your shell rc file, it skips that step.

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License

MIT