Bug 1143013 - Ensure b2g_build passes number of cores to commands to …

…workaround any previous -j settings r=catlee

mozharness/mozilla/building/buildb2gbase.py

@@ -434,7 +434,7 @@ def checkout_sources(self):
                     self.run_command(cmd, cwd=dirs['work_dir'])
 
                 config_result = self.run_command([
-                    './config.sh', '-q', self.config['target'], manifest_filename,
+                    './config.sh', '-j100', '-q', self.config['target'], manifest_filename,
                 ], cwd=dirs['work_dir'], output_timeout=55 * 60)
 
                 # TODO: Check return code from these? retry?

scripts/b2g_build.py

@@ -12,6 +12,7 @@
 import tempfile
 from datetime import datetime
 import urlparse
+import multiprocessing
 import xml.dom.minidom
 
 try:
@@ -545,6 +546,11 @@ def generate_build_command(self, target=None):
             # Workaround bug 984061
             if target == 'package-tests':
                 cmd.append('-j1')
+            else:
+                # Ensure we always utilize the correct number of cores
+                # regardless of the configuration which may be set by repo
+                # config changes...
+                cmd.append('-j{}'.format(multiprocessing.cpu_count()))
             cmd.append(target)
         return cmd