For example I have two (A that generates apk, B that generates aar) fully configured projects (.buckconfig, .git and so on). What I need to do to make my project A depends on B? For example I want to be able to enter B project directory and type "buck build Bproject" to generate my aar. Also it would be great if there is some trick is available to make A -> (B -> C) dependency. Thanks!
This feature is coming to Buck in the future (see issue #116 in the Github repository), however it is not supported yet. For now you will likely have to use a workaround, such as put both projects into the same repository or build the aar of project B, check it into the repository of project A and reference it from an android_prebuilt_aar rule.