Got Stuck When Installing Octave in High Sierra
The installation appears to be waiting on installing gcc. Take the following measures one by one.


If the installation is still stuck at make, cancel it by pressing Control + c.
Enter brew cleanup --prune=0 to clear the local cache.
Enter brew update followed by brew upgrade to update the local cache of package repository.
Run brew config and check the output corresponding to CLT: key. It should shaw the version of installed Command Line Tools. If it says NA, install Command Line Tools by executing xcode-select --install.
Once Command Line Tools are done installing, confirm by observing the output of brew config.
Reattempt installation of Octave by running brew install octave.