When installing with npm i -g google-cloud-gui , you may encounter repeating:

gyp WARN EACCES user "root" does not have permission to access the dev dir "/usr/local/lib/node_modules/google-cloud-gui/node_modules/grpc/.node-gyp/8.11.1"
gyp WARN EACCES attempting to reinstall using temporary dev dir "/usr/local/lib/node_modules/google-cloud-gui/node_modules/grpc/.node-gyp"

Best workaround is to use Yarn - yarn global add google-cloud-gui

Another possible, less recommended workaround, is to use --unsafe-perm flag like so: npm i -g google-cloud-gui --unsafe-perm as discussed here: nodejs/node-gyp#454

If anyone can propose a proper fix, that would be most welcome.