title: avr-g++ compilation failed with Make Error 1
body: <p>I'm trying to compile Arduino code in Eclipse. Below is the build log.</p>
  
  <pre><code>make all 
  Building file: ../test.cpp
  Starting C++ compile
  "/bin/avr-g++" -c -g -Os -w -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=163 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR     -I"/opt/arduino-1.6.3/hardware/arduino/avr/cores/arduino" -I"/opt/arduino-1.6.3/hardware/arduino/avr/variants/standard" -I/usr/lib/avr/include -MMD -MP -MF"test.cpp.d" -MT"test.cpp.d" -D__IN_ECLIPSE__=1 -x c++ "../test.cpp"  -o  "test.cpp.o"
  as: unrecognized option '-mmcu=avr5'
  make: *** [test.cpp.o] Error 1
  </code></pre>
  
  <p>What's wrong? What does <code>as: unrecognized option '-mmcu=avr5'</code> mean? It can't recognize the <code>-mmcu</code> option? </p>