title: NPM won't install any package on Mac. New, clean build. `EACCES` & other errors
body: <p>I've just rebuild my Mavericks (Mac OS X Version 9.4) machine from scratch. I am the administrator and only user of this machine. </p>
  
  <ul>
  <li>I installed Git via their <code>git-2.0.1-intel-universal-snow-leopard.pkg</code> (<a href="http://git-scm.com/downloads" rel="noreferrer">http://git-scm.com/downloads</a>) in their default <code>/usr/local/git/bin/git</code> location. </li>
  <li>I installed Node via their <code>node-v0.10.30.pkg</code> (<a href="http://nodejs.org/download/" rel="noreferrer">http://nodejs.org/download/</a>) in their default <code>/usr/local/bin/node</code> location. </li>
  <li>The final step of Node's installer package included a note that they also installed NPM in their default <code>/usr/local/bin/npm</code> location.</li>
  <li>My <code>$PATH</code> echoes <code>/usr/local/git/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/local/git/bin</code> (it contains <code>/usr/local/bin</code>). </li>
  </ul>
  
  <p>Running <code>npm install -g bower</code> results in: </p>
  
  <pre><code>npm ERR! Error: EACCES, mkdir '/usr/local/lib/node_modules/bower'
  npm ERR!  { [Error: EACCES, mkdir '/usr/local/lib/node_modules/bower']
  npm ERR!   errno: 3,
  npm ERR!   code: 'EACCES',
  npm ERR!   path: '/usr/local/lib/node_modules/bower',
  npm ERR!   fstream_type: 'Directory',
  npm ERR!   fstream_path: '/usr/local/lib/node_modules/bower',
  npm ERR!   fstream_class: 'DirWriter',
  npm ERR!   fstream_stack: 
  npm ERR!    [ '/usr/local/lib/node_modules/npm/node_modules/fstream/lib/dir-writer.js:36:23',
  npm ERR!      '/usr/local/lib/node_modules/npm/node_modules/mkdirp/index.js:37:53',
  npm ERR!      'Object.oncomplete (fs.js:107:15)' ] }
  npm ERR! 
  npm ERR! Please try running this command again as root/Administrator.
  
  npm ERR! System Darwin 13.3.0
  npm ERR! command "node" "/usr/local/bin/npm" "install" "-g" "bower"
  npm ERR! cwd /Users/Home
  npm ERR! node -v v0.10.30
  npm ERR! npm -v 1.4.21
  npm ERR! path /usr/local/lib/node_modules/bower
  npm ERR! fstream_path /usr/local/lib/node_modules/bower
  npm ERR! fstream_type Directory
  npm ERR! fstream_class DirWriter
  npm ERR! code EACCES
  npm ERR! errno 3
  npm ERR! stack Error: EACCES, mkdir '/usr/local/lib/node_modules/bower'
  npm ERR! fstream_stack /usr/local/lib/node_modules/npm/node_modules/fstream/lib/dir-writer.js:36:23
  npm ERR! fstream_stack /usr/local/lib/node_modules/npm/node_modules/mkdirp/index.js:37:53
  npm ERR! fstream_stack Object.oncomplete (fs.js:107:15)
  npm ERR! 
  npm ERR! Additional logging details can be found in:
  npm ERR!     /Users/Home/npm-debug.log
  npm ERR! not ok code 0
  </code></pre>
  
  <p>Running similar installations (<code>npm install -g yo</code>, <code>npm install -g grunt</code>, <code>npm install -g nvm</code>, <code>npm install -g npm</code>) results in what appears to be the same list of errors. </p>
  
  <p>Several people online suggest forcing the installation via <code>sudo</code>, but several others warn this could cause later issues. The manuals for these packages seem not to mention requirement of <code>sudo</code>, and in some cases, they have advised contacting NPM when this issue arises. </p>
  
  <p>Running <code>npm cache clear</code> does not correct the issue. </p>
  
  <p>Running <code>ls -la</code> in the home (<code>~</code>) directory shows my Mac OS X username as the owner of my <code>.npm</code> directory: <code>drwxr-xr-x    15 admin  staff    510 Aug 11 23:53 .npm</code></p>
  
  <p>Does anyone know what has gone wrong and how to correct this? Thank you. </p>