As expected the guide for Gentoo is a little out of date on the Arduino web site.
Here are some quick fixes to get the IDE up and running.
1) Set Sun(Oracle) JRE or JDK as your system Java vm (Ice tea will make Arduino IDE fail) I am using the JDK ( sun-jdk-1.6 system-vm)
2) Building the tool chain. I had to remove the "-S" stable flag from the crossdev build would fail every-time.
$ USE="-openmp" crossdev -t avr -s4 --without-headers
3) I had issues compiling my Arduino test code it complained at the two following things :
`` "/usr/libexec/gcc/avr/ld: cannot open linker script file ldscripts/avr5.x: No such file or directory collect2: ld returned 1 exit status"
To fix I made the following sym link :
$ ln -s /usr/x86_64-pc-linux-gnu/avr/lib/ldscripts /usr/avr/lib/ldscripts
Next error :
"/usr/libexec/gcc/avr/ld: cannot find crtm328p.o: No such file or directory collect2: ld returned 1 exit status"
Once again fixed with another sym link :
$ ln -s /usr/avr/lib/avr5/crtm328p.o /usr/avr/lib/crtm328p.o
4) Use the current Arduino build from there web site the one in the portage overlay is way out of date. I used the pre-compiled java binary with no issues from <a title="Linux x86_64 software" href="http://arduino.cc/en/Main/Software">hear</a>. If you don't use the latest one you may get an error like this :
"avrdude: AVR Part "atmega328p" not found." ```
Thats it! all up and running and writing code for it now.