请教关于CC2538DK+contiki下载程序问题

您好，
我现在刚购买一套CC2538DK开发套件，里面有2套SmartRF06+CC2538子板，想运行一下Contiki 3.0中CC2538的例子，在Instant Contiki用make编译生成/contiki-release-3-0/examples/cc2538dk中的例子，得到cc2538-demo.elf和cc2538-demo.bin等文件。但是当运行make cc2538-demo.upload的时候，显示如下错误：
using saved target 'cc2538dk'
fatal: Not a git repository: '../../.git'
CC ../../cpu/cc2538/./ieee-addr.c
AR contiki-cc2538dk.a
CC ../../cpu/cc2538/cc2538.lds
CC ../../cpu/cc2538/./startup-gcc.c
CC cc2538-demo.c
LD cc2538-demo.elf
ARM-none-eabi-objcopy -O binary --gap-fill 0xff cc2538-demo.elf cc2538-demo.bin
python ../../tools/cc2538-bsl/cc2538-bsl.py -e -w -v cc2538-demo.bin
File "../../tools/cc2538-bsl/cc2538-bsl.py", line 5

^
SyntaxError: invalid syntax
make: *** [cc2538-demo.upload] Error 1
rm cc2538-demo.co obj_cc2538dk/startup-gcc.o
烧写程序按照https://github.com/contiki-os/contiki/blob/master/platform/cc2538dk/README.md这里面Build your First Examples的方法来做，但显示如上错误。不知道是什么原因？谢谢