# 3. Setting up your environment

Set up your environment variables (as indicated in the output of the configure script).

```bash
cd $HOME/build/pylith
source setup.sh
```

:::{warning}
The `setup.sh` script works for terminals running the bash shell. If you are using a different shell, you will need to modify the script to set the environment variables using the appropriate syntax.
:::

:::{important}
You must run the `source setup.sh` script in each terminal you run `configure` *and* before each time you run PyLith.

To avoid having to run `source setup.sh` each time, you can add the corresponding environment variables to your `.bashrc` file (or equivalent for other shells).
:::