I have exactly this same problem when installing the latest Ionic 2 CLI - an error message containing “ENOENT … ansi”:
ENOENT: no such file or directory … ansi-e14136a8
I’m running node 6.9.1 and npm 3.10.8 (these are stable ‘LTS’ versions although not the very latest).
I also see a Github issue about this problem, and it also includes a solution:
Haven’t tried it but the solution is supposed to be to do a “npm -g remove ionic” first before installing the new version.