title: node-gyp rebuild Fail on Mac OSX El Capitan
body: <p>I have a problem with <code>node-gyp rebuild</code>
  Now I'm using xcode Version 7.2.1 (7C1002) and when I install the library like
  <code>libxmljs@0.14.3</code> I have this error</p>
  
  <pre><code>gyp ERR! stack     at ChildProcess.emit (events.js:110:17)
  gyp ERR! stack     at Process.ChildProcess._handle.onexit (child_process.js:1074:12)
  gyp ERR! System Darwin 15.3.0
  gyp ERR! command "node" "/Users/bob/.nvm/versions/node/v0.12.6/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
  gyp ERR! cwd /Users/bob/Documents/Lavori/dg/workbook-app/node_modules/gulp-xml-editor/node_modules/libxmljs
  gyp ERR! node -v v0.12.6
  gyp ERR! node-gyp -v v2.0.1
  gyp ERR! not ok
  npm ERR! Darwin 15.3.0
  npm ERR! argv "/Users/bob/.nvm/versions/node/v0.12.6/bin/node" "/Users/bob/.nvm/versions/node/v0.12.6/bin/npm" "install"
  npm ERR! node v0.12.6
  npm ERR! npm  v2.11.2
  npm ERR! code ELIFECYCLE
  
  npm ERR! libxmljs@0.14.3 install: `node-gyp rebuild`
  npm ERR! Exit status 1
  npm ERR!
  npm ERR! Failed at the libxmljs@0.14.3 install script 'node-gyp rebuild'.
  npm ERR! This is most likely a problem with the libxmljs package,
  npm ERR! not with npm itself.
  npm ERR! Tell the author that this fails on your system:
  npm ERR!     node-gyp rebuild
  npm ERR! You can get their info via:
  npm ERR!     npm owner ls libxmljs
  npm ERR! There is likely additional logging output above.
  </code></pre>
  
  <p>I tried with NVM with this node version</p>
  
  <p>nvm 0.12.6 | nvm 0.12.7</p>
  
  <p>But I have the same Problem</p>
  
  <p>With command `node-gyp rebuild``</p>
  
  <p>I have this output</p>
  
  <pre><code>gyp ERR! configure error
  gyp ERR! stack Error: `gyp` failed with exit code: 1
  gyp ERR! stack     at ChildProcess.onCpExit (/usr/local/lib/node_modules/node-gyp/lib/configure.js:305:16)
  gyp ERR! stack     at ChildProcess.emit (events.js:110:17)
  gyp ERR! stack     at Process.ChildProcess._handle.onexit (child_process.js:1074:12)
  gyp ERR! System Darwin 15.3.0
  gyp ERR! command "node" "/usr/local/bin/node-gyp" "rebuild"
  gyp ERR! cwd /my-path
  gyp ERR! node -v v0.12.7
  gyp ERR! node-gyp -v v3.2.1
  gyp ERR! not ok
  </code></pre>