File fix-build.patch of Package uranium-firmware2-lulzbot

diff --git a/Marlin/Makefile b/Marlin/Makefile
index ce267a379..34f42edf5 100644
--- a/Marlin/Makefile
+++ b/Marlin/Makefile
@@ -750,8 +750,8 @@ LST = $(LIB_ASRC:.S=.lst) $(LIB_CXXSRC:.cpp=.lst) $(LIB_SRC:.c=.lst)
 
 # Combine all necessary flags and optional flags.
 # Add target processor to flags.
-ALL_CFLAGS   = $(MCU_FLAGS) $(CPU_FLAGS) $(CFLAGS) -I.
-ALL_CXXFLAGS = $(MCU_FLAGS) $(CPU_FLAGS) $(CXXFLAGS)
+ALL_CFLAGS   = $(MCU_FLAGS) $(CPU_FLAGS) $(CFLAGS) -I. -I/usr/avr/sys-root/include/
+ALL_CXXFLAGS = $(MCU_FLAGS) $(CPU_FLAGS) $(CXXFLAGS) -I/usr/avr/sys-root/include/
 ALL_ASFLAGS  = $(MCU_FLAGS) $(CPU_FLAGS) $(ASFLAGS) -x assembler-with-cpp
 
 # set V=1 (eg, "make V=1") to print the full commands etc.