If you don't do so, the `pip` command later will handle installing from PyPI.
**Optionally**, if you want the GUI, you'll need QT5 installed. If you're on Debian or Ubuntu, this might work:
You can install most or all of the dependencies using the Debian or Ubuntu distribution repositories using the following command. If you install them all, the `pip install` commands later should do nothing.
Finally, as a user install glance. If you want to force a local install, perhaps for testing, omit `--system-site-packages`. Run these as your normal user:
**If** you didn't install the system-wide packages, you'll need basic build tools to install some modules (at least cartopy). In that case, you'll need this. It's about 100 MiB on a _minimal_ Ubuntu install.
As root:
```
apt install -y build-essentials python3-dev
```
**IF** you didn't install the system-wide packages, and you want GUI support, you'll need the QT5 library. It's about 360 MiB on a _minimal_ Ubuntu install.
As root:
```
apt install -y libqt5gui5
```
Finally, as a user install glance. The `pip install` should do no actual installs for any system-wide modules that are present. Alternatively, you can omit `--system-site-packages` to force local installed, perhaps for testing.