Is there anything we can do to help this move forward? There are some features missing that are a deal breaker for some projects!
Thanks! :)

For those in need of using the latest version of the Arduino Core (1.8.6 as of today), I will be maintaing a repository with an upstream copy of the core with minimal modifications to make it work with platformio (package.json). It isn't my idea to fork this package, or to be maintaining this forever, but to have a working package until this one can be updated. For that very same reason I will not be publishing that repo in platformio's registry. If you need a different version let me know so I can add it :)

To use this repository in your project:

platform_packages =
	framework-arduino-avr @ https://github.com/fermino/framework-arduino-avr-upstream#upstream-1.8.6

@fermino
first of all thanks for your effort, I'm compiling in Linux and there is a problem using your repo

config:

[env]
platform = https://github.com/platformio/platform-atmelavr.git
platform_packages = https://github.com/fermino/framework-arduino-avr-upstream#upstream-1.8.6
framework = arduino
board = controllino_maxi

error:

Resolving release dependencies...
Tool Manager: Installing platformio/framework-arduino-avr @ ~5.1.0
Unpacking 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Tool Manager: framework-arduino-avr@5.1.0 has been installed!
Tool Manager: Installing framework-arduino-avr-upstream @ *
UnknownPackageError: Could not find the package with 'framework-arduino-avr-upstream @ *' requirements for your system 'linux_x86_64'

Just tested it... no luck

UnknownPackageError: Could not find the package with 'framework-arduino-avr-upstream @ *' requirements for your system 'linux_x86_64'

@labodj I didn't see it, you're missing the framework-arduino-avr @ part in platform_packages. Without that PIO assumes the package name is framework-arduino-avr-upstream, which has the extra -upstream

Try with this:

platform = atmelavr
platform_packages = framework-arduino-avr @ https://github.com/fermino/framework-arduino-avr-upstream#upstream-1.8.6
framework = arduino
board = controllino_maxi

@fermino thanks it was an oversigth, now it works as expected!
Anyway it's compatible with few boards (EG: not controllino)...
I just opened a pull request to add current platformio supported boards here: fermino/framework-arduino-avr-upstream#1