--- a/contrib/dockerlib.sh	Mon Nov 09 10:43:23 2015 -0800
+++ b/contrib/dockerlib.sh	Sun Nov 08 01:10:52 2015 +0800
@@ -35,8 +35,8 @@
         # running docker. This is *very likely* to fail at some point.
         echo RUN useradd $DBUILDUSER -u 1000
     else
-        echo RUN groupadd $DBUILDUSER -g `id -g`
-        echo RUN useradd $DBUILDUSER -u `id -u` -g $DBUILDUSER
+        echo RUN groupadd $DBUILDUSER -g `id -g` --non-unique
+        echo RUN useradd $DBUILDUSER -u `id -u` -g $DBUILDUSER --non-unique
     fi
   ) | $DOCKER build --tag $CONTAINER -
 }