ci.diff

diff --git a/lib/utils.js b/lib/utils.js
index c90dd6b0..0c5ae37f 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -6,7 +6,7 @@
 const assert = require('assert');
 const urlParse = require('url').parse;
 const path = require('path');
-const exec = require('child_process').exec;
+const processSpawn = require('child_process').spawn;
 
 const _ = require('lodash');
 const Q = require('q');
@@ -27,18 +27,30 @@ const debug = require('debug')('serp:q-utils');
  */
 exports.execPromise = function(cmd, cwd) {
     const defer = Q.defer();
-    const maxBuffer = 1024 * 1024; // 1Mb
+    const stdOut = [];
+    const stdErr = [];
 
     debug(`executing: "${cmd}" in "${cwd}"`);
-    exec(cmd, { cwd, maxBuffer }, (err, stdout, stderr) => {
-        if (stderr) {
-            debug(`>>> "${cmd}" stderr:`, stderr);
-        }
-        if (stdout) {
-            debug(`>>> "${cmd}" stdout:`, stdout);
+
+    processSpawn(cmd, { cwd });
+
+    processSpawn.stdout.on('data', (data) => {
+        debug(`>>> "${cmd}" stdout:`, data);
+        stdOut.push(data);
+    });
+
+    processSpawn.stderr.on('data', (data) => {
+        debug(`>>> "${cmd}" stderr:`, data);
+        stdErr.push(data);
+    });
+
+    processSpawn.on('close', (code) => {
+        debug(`child process exited with code ${code}`);
+        if (code !== 0) {
+            return defer.reject(stdErr.join(''));
         }
 
-        return err ? defer.reject(err) : defer.resolve(stdout);
+        defer.resolve(stdOut.join(''));
     });
 
     return defer.promise;