diff -r 08b780ecc611 -r 63477d92411d prebuild.sh
--- a/prebuild.sh	Wed May 31 12:22:36 2017 +0200
+++ b/prebuild.sh	Wed May 31 12:32:22 2017 +0200
@@ -22,7 +22,7 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 
 autoreconf -i
-mkdir build
+mkdir -p build
 cd build
 ../configure $*