Add some information to error message

I had to put this change in to spot where my typo was, so thought I would make a PR

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/async.js b/lib/async.js
index 3748ac0..2e4e3c6 100644
--- a/lib/async.js
+++ b/lib/async.js
@@ -575,7 +575,7 @@
             var dep;
             while (len--) {
                 if (!(dep = tasks[requires[len]])) {
-                    throw new Error('Has inexistant dependency');
+                    throw new Error('Has inexistant dependency in ' + requires.join(', '));
                 }
                 if (_isArray(dep) && _indexOf(dep, k) >= 0) {
                     throw new Error('Has cyclic dependencies');