--save-prefix is undocumented and allows "@"

[sam-github]

I can't find it mentioned by npm help install, oversight?

Also, npm install --save --save-prefix "@" once "works"... but isn't valid, what's with that?

[sam-github]

And once the @ is in the packages.json, you can't call npm install anymore to save with a new prefix:

npm-workshop ~/w/nc/npm-tutor> npm install --save --save-prefix '>=' once
npm WARN package.json [email protected] No description
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No README data
npm ERR! notarget No compatible version found: once@'@1.3.0'
npm ERR! notarget Valid install targets:
npm ERR! notarget ["1.1.1","1.2.0","1.3.0"]
npm ERR! notarget 
npm ERR! notarget This is most likely not a problem with npm itself.
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist.

npm ERR! System Linux 3.11.0-24-generic
npm ERR! command "/usr/local/bin/node" "/usr/local/bin/npm" "install" "--save" "--save-prefix" ">=" "once"
npm ERR! cwd /home/sam/w/nc/npm-tutor
npm ERR! node -v v0.10.29
npm ERR! npm -v 1.4.14
npm ERR! code ETARGET
npm ERR! 
npm ERR! Additional logging details can be found in:
npm ERR!     /home/sam/w/nc/npm-tutor/npm-debug.log
npm ERR! not ok code 0
npm-workshop ~/w/nc/npm-tutor> grep once package.json 
    "once": "@1.3.0",