lib/package: Handle EPERM/EACCES errors on fs.rename caused by antivi…

…rus programs in Windows locking newly created dirs.

lib/package.js

@@ -62,6 +62,29 @@ var unpack = function(zip, dest, cb) {
 }
 
 var package = module.exports;
+var move = function(from, to, cb) {
+  if (process.platform != 'win32')
+    return fs.rename(from, to, cb);
+
+  // on windows, antivirus softwares lock new folders until all files are scanned
+  // which causes a EPERM error when doing a fs.rename. to prevent this from ruining
+  // the process, we'll retry the fs.rename 10 times every one second if we do get a EPERM error.
+  function like_a_boss(attempt) {
+    fs.rename(from, to, function(err) {
+
+      // if no error, or err is not EPERM/EACCES, we're done
+      if (!err || (err.code != 'EPERM' && err.code != 'EACCES'))
+        cb();
+      else if (attempt >= 10) // max attempts reached, so give up.
+        cb(err);
+      else
+        setTimeout(function() { like_a_boss(attempt + 1) }, 1000);
+
+    })
+  }
+
+  like_a_boss(1);
+}
 
 package.verify_checksum = function(version, filename, file, cb) {
 
@@ -230,7 +253,7 @@ package.install = function(zip, dest, cb) {
       if (err) return done(err);
 
       log('Renaming to ' + final_path);
-      fs.rename(new_path, final_path, function(err) {
+      move(new_path, final_path, function(err) {
         if (err) return done(err);
 
         // make absolutely sure that the bins are executable!