npm install -g ember-cli fails on Mac OS Catalina Version 10.15.4

Output from ember version --verbose && npm --version && yarn --version:

zsh: command not found: ember

This is my first encounter with npm install -g ember-cli and on running the command I am getting this o/p

npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated
npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
npm WARN deprecated @babel/polyfill@7.8.7: 🚨 This package has been deprecated in favor of separate inclusion of a polyfill and regenerator-runtime (when needed). See the @babel/polyfill docs (https://babeljs.io/docs/en/babel-polyfill) for more information.
npm WARN deprecated core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
npm ERR! Unexpected end of JSON input while parsing near '...textextensions","vers'

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/apple/.npm/_logs/2020-05-27T06_44_20_555Z-debug.log

You can find contents of /Users/apple/.npm/_logs/2020-05-27T06_44_20_555Z-debug.log in this gist

I am using Mac OS Catalina Version 10.15.4

Any help is appreciated.

[rwjblue]

When you install a package (with any package manager, e.g. npm, yarn, pnpm, etc) it downloads a compressed file (usually a .tar.gz file). It caches that downloaded tarball so that it can avoid fetching the same file repeatedly from the network. In this case, I suspect that the downloaded file itself was corrupted (perhaps from a network interruption, a bug in the NPM registry, etc) but it was still placed into your cache. When the tarball was unpacked and used it was malformed and caused the error you reported. Since it was stored in your global cache, even repeated re-installs would hit the same problem. Clearing the cache purges the malformed tarball so that a subsequent install can not error.

[jupiter888]

that really helped me understand about duplications handling!!! interesting, thank you