--- a/configure.py	
+++ a/configure.py	
@@ -717,4 +717,6 @@ if options.bootstrap:
     if options.verbose:
         rebuild_args.append('-v')
 
+    print(' '.join(rebuild_args))
+    print('debug me with: gdb --args ' + ' '.join(rebuild_args))
     subprocess.check_call(rebuild_args)