add OSMESA_LIB_NAME
diff --git a/configs/bluegene-osmesa b/configs/bluegene-osmesa
index 8e5a54b..02c69e6 100644
--- a/configs/bluegene-osmesa
+++ b/configs/bluegene-osmesa
@@ -15,6 +15,8 @@
 
 MKLIB_OPTIONS = -static
 
+OSMESA_LIB_NAME = libOSMesa.a
+
 # Directories
 SRC_DIRS = mesa glu
 DRIVER_DIRS = osmesa