Any particular reason why this is done? I'm just a bit confused

Why not treat the project directory as the folder thats going to be included?

Asking, because: Is this some kind of convention or best practice I'm not following or more of a personal taste thing?

On my project, I have a structure in a way that every external libaries are placed into root/external/... folder and added as submodule, then I could add the headers in Android.mk with LOCAL_C_INCLUDES.

Other libaries such as rapidjson and spdlog use this structure so I could add it cleanly but x-watcher doesn't.

LOCAL_C_INCLUDES := \
    $(LOCAL_PATH)/include \
    $(LOCAL_PATH)/external/rapidjson/include \
    $(LOCAL_PATH)/external/spdlog/include

I don't like adding external libraries on my project's include path, hence i proposed this pr, doing this is just make the overall project structure and integrations cleaner.

If you asking if this are some kind of best practice, I'm not sure but most major libraries also does the same thing too so yeah...

Seems fine by me in that case, I don't want to deviate from the norm. I will have to add a warning about existing build scripts breaking due to this.

PS: Thanks for the insight. I made this library only because I was frustrated by a lack of a "all-in-one" solution, so I didn't dig deep to find what specific project structure should be the best as C just lets you do whatever you want. (Kind of a trend I'm noticing since I'm writing way more Rust now)