trouble compiling on 1.6.8

hi,

i get following error message when compiling with ide 1.6.8 on linux. Unbekannte Option means unknown option. Version 1.6.7 was working

Arduino: 1.6.8 (Linux), Board: "Arduino/Genuino Uno"

/opt/arduino-1.6.8/arduino-builder -dump-prefs -logger=machine -hardware "/opt/arduino-1.6.8/hardware" -tools "/opt/arduino-1.6.8/tools-builder" -tools "/opt/arduino-1.6.8/hardware/tools/avr" -built-in-libraries "/opt/arduino-1.6.8/libraries" -libraries "/home/donhomer/Arduino/libraries" -fqbn=arduino:avr:uno -ide-version=10608 -build-path "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp" -warnings=all -prefs=build.warn_data_percentage=75 -verbose "/tmp/untitled2023830890.tmp/sketch_apr01a/sketch_apr01a.ino"
/opt/arduino-1.6.8/arduino-builder -compile -logger=machine -hardware "/opt/arduino-1.6.8/hardware" -tools "/opt/arduino-1.6.8/tools-builder" -tools "/opt/arduino-1.6.8/hardware/tools/avr" -built-in-libraries "/opt/arduino-1.6.8/libraries" -libraries "/home/donhomer/Arduino/libraries" -fqbn=arduino:avr:uno -ide-version=10608 -build-path "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp" -warnings=all -prefs=build.warn_data_percentage=75 -verbose "/tmp/untitled2023830890.tmp/sketch_apr01a/sketch_apr01a.ino"
Build options changed, rebuilding all
"/opt/arduino-1.6.8/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10608 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-I/opt/arduino-1.6.8/hardware/arduino/avr/cores/arduino" "-I/opt/arduino-1.6.8/hardware/arduino/avr/variants/standard" "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp/sketch/sketch_apr01a.ino.cpp" -o "/dev/null"
"/opt/arduino-1.6.8/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10608 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-I/opt/arduino-1.6.8/hardware/arduino/avr/cores/arduino" "-I/opt/arduino-1.6.8/hardware/arduino/avr/variants/standard" "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp/sketch/sketch_apr01a.ino.cpp" -o "/dev/null"
"/opt/arduino-1.6.8/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10608 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-I/opt/arduino-1.6.8/hardware/arduino/avr/cores/arduino" "-I/opt/arduino-1.6.8/hardware/arduino/avr/variants/standard" "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp/sketch/sketch_apr01a.ino.cpp" -o "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp/preproc/ctags_target_for_gcc_minus_e.cpp"
"/opt/arduino-1.6.8/tools-builder/ctags/5.8-arduino10/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp/preproc/ctags_target_for_gcc_minus_e.cpp"
"/opt/arduino-1.6.8/hardware/tools/avr/bin/avr-g++" -c -g -Os -Wall -Wextra -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10608 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-I/opt/arduino-1.6.8/hardware/arduino/avr/cores/arduino" "-I/opt/arduino-1.6.8/hardware/arduino/avr/variants/standard" "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp/sketch/sketch_apr01a.ino.cpp" -o "/tmp/builda58bd892d1b49f4c7bd1d33bbbf4e360.tmp/sketch/sketch_apr01a.ino.cpp.o"
as: Unbekannte Option »-mmcu=avr5«
exit status 1
Error compiling for board Arduino/Genuino Uno.

Script is basically empty:

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

I installed it by simply copying the files as root to /opt/arduino…

A bunch of people have had IDE 1.6.x problems, including IDE crashes and bizarre compile errors, when they had a previous 1.5.x/1.6.x installation. At least some of those problems seem to be caused by out-of-date executables that the IDE saves outside the IDE installation directory. Perhaps that is what is causing your particular problem. In such cases it appears that the fix is to delete or rename the old "Arduino15" directory and re-install 1.6.x.

On Mac OS X:
/Users/(username)/Library/Arduino15

On Windows:
C:\Users(username)\AppData\Roaming\Arduino15

On Linux:
/home/(username)/.arduino15 (a.k.a. ~/.arduino15)