How to debug gulpfile.js

What is the proper way to execute node-inspector in order to be able to debug gulpfile.js?

I've tried following (code in my gulpfile requires harmony and harmony-arrow-functions switches):

node-debug --nodejs --harmony --nodejs --harmony-arrow-functions /home/user/.npm-packages/bin/gulp default

Node inspector was properly loaded however it was not possible to set breakpoint in gulpfile neither before nor after the file was loaded. It was also not possible to set breakpoints in gulp/index.js and orchestrator/index.js files. And it was not possible to "step into" following statement (whole source):

gulpInst.start.apply(gulpInst, toRun);

Environment:

• Fedora 21 x64


• Node Inspector v0.9.2


• node v0.12.0


• gulp
  
  
  
  • CLI version 3.8.11
  
  
  • Local version 3.8.11