core architecture avrxmega3 not supported

[J T]

Cannot compile programs for new ATtiny devices like ATtiny214/414/814 under avr-gcc(GCC) 5.4.0 from Ubuntu packages.
To work with new devices it is mandatory to use ATMEL packs from http://packs.download.atmel.com/

According to note in toolchain source source: http://distribute.atmel.no/tools/opensource/Atmel-AVR-GNU-Toolchain/3.6.0/:
"
How to use Atmel DFPs with Stanadalone toolchain?

# Download DFP from here (e.g. Atmel.ATmega_DFP.1.0.86.atpack)
# Unzip .atpack to packs directory (/home/packs/)
# Invoke avr-gcc with additional option -B to tell gcc where to look for device specific information
    e.g. avr-gcc -mmcu=atmega328pb -B /home/packs/Atmel.ATmega_DFP.1.0.86/gcc/dev/atmega328pb/ -I /home/packs/Atmel.ATmega_DFP.1.0.86/include/
"

It works OK for new ATmega devices, but some new ATtiny models has avrxmega3 core and avr-gcc produces this error message:

error: unknown core architecture ‘avrxmega3’ specified with ‘-mmcu=’

Also there is no directory avrxmega3 in /usr/lib/gcc/avr/5.4.0

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ronald Sutherland (rsutherland)]

Microchip has made the source available for there AVR GCC 3.6.2 toolchain, which should provide the needed architectures for the new devices. The Debian maintain may need to be shown this link.

https://www.microchip.com/mplab/avr-support/avr-and-sam-downloads-archive

Thanks