Permission denied when installing npm modules in OSX

I'm trying to install node-g.raphael, and I'm getting the following error:

Bender-03:htdocs alfred$ sudo npm install node-g.raphael --save
Password:

> contextify@0.1.15 install 
  /Users/alfred/Sites/twistedgeo/htdocs/node_modules/contextify
> node-gyp rebuild

gyp ERR! configure error
gyp ERR! stack Error: EACCES: permission denied, mkdir 
  '/Users/alfred/Sites/twistedgeo/htdocs/node_modules/contextify/build'
gyp ERR! System Darwin 16.7.0
gyp ERR! command "/usr/local/bin/node" 
  "/usr/local/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" 
  "rebuild"
gyp ERR! cwd 
  /Users/alfred/Sites/twistedgeo/htdocs/node_modules/contextify
gyp ERR! node -v v8.8.1
gyp ERR! node-gyp -v v3.6.2
gyp ERR! not ok
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: contextify@0.1.15 
  (node_modules/contextify):
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: contextify@0.1.15 
  install: `node-gyp rebuild`
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: Exit status 1

+ node-g.raphael@0.0.9
added 2 packages and updated 1 package in 6.556s

I've tried this solution, but it doesn't solve my problem, still getting the same error.

Let me know if there's anything I can add to help in solving this.

Saw this from Fixing npm permissions and it helped, maybe you could give it a shot as well.

Option 1: Change the permission to npm's default directory

1. Find the path to npm's directory:

   npm config get prefix

For many systems, this will be /usr/local.

WARNING: If the displayed path is just /usr, switch to Option 2 or you will mess up your permissions.

2. Change the owner of npm's directories to the name of the current user (your username):

   sudo chown -R $(whoami) $(npm config get prefix)/{lib/node_modules,bin,share}

This changes the permissions of the sub-folders used by npm and some other tools (lib/node_modules, bin, and share).

Option 2: Change npm's default directory to another directory

There are times when you do not want to change ownership of the default directory that npm uses (i.e. /usr) as this could cause some problems, for example if you are sharing the system with other users.

Instead, you can configure npm to use a different directory altogether. In our case, this will be a hidden directory in our home folder.

1. Make a directory for global installations:

   mkdir ~/.npm-global

2. Configure npm to use the new directory path:

   npm config set prefix '~/.npm-global'

3. Open or create a ~/.profile file and add this line:

   export PATH=~/.npm-global/bin:$PATH

4. Back on the command line, update your system variables:

   source ~/.profile

Test: Download a package globally without using sudo.

`npm install node-g.raphael --save`

Instead of steps 2-4, you can use the corresponding ENV variable (e.g. if you don't want to modify ~/.profile):

NPM_CONFIG_PREFIX=~/.npm-global

Option 3: Use a package manager that takes care of this for you.

If you're doing a fresh install of Node on Mac OS, you can avoid this problem altogether by using the Homebrew package manager. Homebrew sets things up out of the box with the correct permissions.

brew install node