How to get Haskell Stack to dynamically link with C?

Suppose we have a project with the following structure

.
├── CHANGELOG.md
├── LICENSE
├── README.md
├── Setup.hs
├── app
│   └── Main.hs
├── cbits
│   ├── include
│   │   └── libCbits.c
│   └── lib
│       └── libCbits.so
├── dummy.cabal
├── package.yaml
├── src
├── stack.yaml
└── stack.yaml.lock

The file libCbits.c needs to be compiled to a .so file every time it updates with which Main.hs be linked.

I've tried adding extra-lib-dirs and extra-include-dirs to package.yml, which did not work.

How do I achieve this goal?

The normal way to do this has the following directory structure instead:

⋮
├── cbits
│   └── libCbits.c
├── dummy.cabal
⋮

There are two changes here:

1. Under normal circumstances, an include directory has .h files only. This is a C convention. If you really want another layer of directory, you could name it cbits/src or cbits/lib or similar instead.
2. It is extremely unusual to manually manage a .so.

Then one puts some stuff like this in the appropriate cabal file:

c-sources: cbits/libCbits.c
cc-options: -O3 (or whatever)

You may be in an extremely unusual situation, where this kind of setup does not work. If so, to get more targeted advice you will probably have to say what you are trying to do that makes this setup unsuitable.