Include relative external library

I have a few projects which should depend on a single custom library

My structure is

– MainFolder
–– ProjectA
––– src
–––– Main.cpp
–– ProjectB
––– src
–––– Main.cpp
– Library
–– library.cpp
–– library.hpp

If for example I do #include “…/…/…/Library/library.hpp” it works until I use #include “Arduino.h” inside of my library. ‘pio run’ inside of ProjectA breaks with library.hpp: “Arduino.h” not found. Is there any way to make it work?

-I “${platformio.workspace_dir}…/…/Library” in build_flags also did not work

Solved with adding library.json to my library and lib_deps = MyLibrary=symlink://…/…/MyLibrary