The dependencies needed to build and install Gnuastro are defined by the features you want and how you would like to obtain the source code (see Downloading the source). A minimal set of dependencies are mandatory, if they are not present you cannot get passed the configuration step. Such mandatory dependencies are therefore very basic (low-level) tools which are easy to obtain, build and install, see Mandatory dependencies for a full discussion.
If you have the packages of Optional dependencies, Gnuastro will have additional functionality (for example converting FITS images to JPEG or PDF). If you are installing from a tarball as explained in Quick start, you can stop reading after this section. However, if you decided to use the version controlled source instead of the tarball (see Version controlled source), an additional bootstrapping step is required before configuration and its dependencies are explained in Bootstrapping dependencies.
|• Mandatory dependencies:||Gnuastro will not install without these.|
|• Optional dependencies:||Adding more functionality.|
|• Bootstrapping dependencies:||If you have the version controlled source.|