Make options.env less surprising

README.md

@@ -113,4 +113,8 @@ You won't need to set this option unless you encounter a "stdout maxBuffer excee
 
 type: `Object`
 
-default: [`process.env`](http://nodejs.org/api/process.html#process_process_env) with `PATH` prepended by `./node_modules/.bin`, allowing you to run executables in your Node's dependencies.
+By default, all the commands will be executed in an environment with all the variables in [`process.env`](http://nodejs.org/api/process.html#process_process_env) and `PATH` prepended by `./node_modules/.bin` (allowing you to run executables in your Node's dependencies).
+
+You can override any environment variables with this option.
+
+For example, setting it to `{PATH: process.env.PATH}` will reset the `PATH` if the default one brings your some troubles.

index.js

@@ -16,17 +16,17 @@ function shell(commands, options) {
     throw new gutil.PluginError(PLUGIN_NAME, 'Missing commands')
   }
 
-  var pathToBin = path.join(process.cwd(), 'node_modules/.bin')
-  var PATH = pathToBin + path.delimiter + process.env.PATH
-
   options = _.extend({
     ignoreErrors: false,
     quiet: false,
     cwd: process.cwd(),
-    env: _.defaults({PATH: PATH}, process.env),
     maxBuffer: 16 * 1024 * 1024
   }, options)
 
+  var pathToBin = path.join(process.cwd(), 'node_modules/.bin')
+  var PATH = pathToBin + path.delimiter + process.env.PATH
+  options.env = _.extend({}, process.env, {PATH: PATH}, options.env)
+
   var stream = through.obj(function (file, unused, done) {
     var self = this