$ gulp
[12:05:33] Using gulpfile ~\Documents\Purescript\gulpfile.js
[12:05:33] Starting 'purescript'...
events.js:85
      throw er; // Unhandled 'error' event
            ^
Error: spawn psc ENOENT
    at exports._errnoException (util.js:746:11)
    at Process.ChildProcess._handle.onexit (child_process.js:1046:32)
    at child_process.js:1137:20
    at process._tickCallback (node.js:355:11)

//gulpfile.js
var gulp = require('gulp');
var purescript = require('gulp-purescript');

gulp.task('purescript', function(){
  return gulp.src('src/**/*.purs').
         pipe(purescript.psc({main:"Chapter2"})). //<-- if this line is commented the script works
         pipe(gulp.dest('build'));
});
gulp.task('default', ['purescript']);

-- Chapter2.purs
module Chapter2 where
import Debug.Trace
main = trace "Hello"

$ node -v
v0.12.1

$ npm -v
2.5.1

$ gulp -v
[12:05:49] CLI version 3.8.11
[12:05:49] Local version 3.8.11

#local node_modules
gulp\
gulp-dest\
gulp-purescript\
gulp-util\
logalot\
minimist\
multipipe\
resolve-bin\
through2\
which\

#this works
john@HOME-PC ~/Documents/Purescript
$ psc src/Chapter2.purs --output dist/Main.js --main=Chapter2 --module=Chapter2