Manually added boards doesn't work in 1.8.5…?

Question

I'm trying to manually add board definitions in a boards.txt file in hardware subfolder of my sketches folder as per instructions here for instance: https://www.arduino.cc/en/Tutorial/ArduinoISP

They however do NOT show up in my board selection.

My sketches location where hardware subfolder should be placed:

Board defs:

~/D/Arduino ❯❯❯ cat ~/Documents/Arduino/hardware/boards.txt
##############################################################

atmega328bb.name=ATmega328 on a breadboard (8 MHz internal clock)

atmega328bb.upload.protocol=arduino
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600

atmega328bb.bootloader.low_fuses=0xE2
atmega328bb.bootloader.high_fuses=0xDA
atmega328bb.bootloader.extended_fuses=0x05

atmega328bb.bootloader.file=atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb.bootloader.unlock_bits=0x3F
atmega328bb.bootloader.lock_bits=0x0F

atmega328bb.build.mcu=atmega328p
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard


atmega328bb.bootloader.tool=arduino:avrdude
atmega328bb.upload.tool=arduino:avrdude

BUT nothing show here:

I have restarted Arduino IDE.

Answer 1

Newer versions of the IDE (after 1.5) have a different folder structure where there is additional subfolders for maintainer and architecture.

<Arduino sketch folder>/hardware/<custom name>/avr/boards.txt

https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5-3rd-party-Hardware-specification