It's not clear to me why you aren't able to checkout the cores under the hardware subfolder of ARDUINO_DIRECTORIES_USER. Would you mind helping me to understand better?
I realize now that I'm actually going to end up with a similar issue around --libraries: I'd really like to be able to include individual libraries in the search path, without having to stick them one extra level deeper in the directory structure so that --libraries /path/to/my-library's-parent-directory/ doesn't attempt pick up ever sibling directory of my library's checkout as a possible library to include.
What I'm really looking for, if this is not indeed possible right now, is some read on whether it's a design decision or just something not-yet-implemented.
I don't believe arduino-builder has that capability. Am I wrong?Arduino CLI's `arduino-cli compile --libraries` provides the same functionality as `arduino-builder -libraries`:https://arduino.github.io/arduino-cli/latest/commands/arduino-cli_compile/#options
It looks like you have libraries bundled with your core though, so it's not clear to me why it would be necessary to specify custom library folders.
I think the best way to proceed is to open a feature request in the Arduino CLI repository's issue tracker.I would suggest providing a clear example of why you need it including the example folder structure you want to create. I'm pretty knowledgeable on this subject and am really making an effort (but I'll confess I didn't study the 700 line script) to understand your use case, but still I can't understand why you need it.That's not to say I'm opposed to adding it. It especially makes sense in the context of Arduino CLI already having an `arduino-cli compile --libraries` option. I just think it never hurts to present a compelling argument when making a feature request. Even if the feature would be added regardless, there's always the question of when it gets added, and a strong argument might bump that work up in the "to-do" list.
I think what I'm trying to figure out is about whether the directory structures supported by arduino-cli are intentionally "opinionated." If Arduino wants developers to keep their code organized in a certain way, I can understand that.