Cannot determine versions of "@angular/cli" local installation is broken

Restore your old package.json / package-lock.json, then delete all your contents of node_modules. After, from your project root run the following to rebuild the contents of node_modules:

npm install.

If you don't have a copy of the package files from before the problems started, first, uninstall moment - local and global - to prevent it from installing itself when you run npm install.

npm uninstall moment ngx-moment

npm uninstall -g moment ngx-moment

Then go with the step of deleting all your node_modules contents before running npm install in your project root.

Please, check your version of @angular/cli (both, local and global) as Angular 8 is released. Also, try to match your version with current ngx-moment's @angular/cli version (i.e. "@angular/cli": "~7.0.3" as of June 2019)