diff --git a/lib/git-beat.js b/lib/git-beat.js
index <HASH>..<HASH> 100644
--- a/lib/git-beat.js
+++ b/lib/git-beat.js
@@ -45,10 +45,19 @@ function GitBeat(options) {
 
 
 GitBeat.prototype.exec = function (cmd, done) {
-  this.logger('exec in "' + this.cwd + '" ' + cmd);
+  var log = this.logger;
+  var cwd = this.cwd;
+  var traceError = new Error('exec in "' + cwd + '" ' + cmd);
+
   exec(cmd, {
     cwd: this.cwd
-  }, done);
+  }, function (err, stdout, stderr) {
+    if (err) {
+      traceError.message += ', \n' + err.message;
+      return done(traceError, stdout, stderr);
+    }
+    done(null, stdout, stderr);
+  });
 };
impr(exec): add the stack trace of exec call

this allows a better troubleshooting