How to set cabal extra dirs for all packages in a sandbox

Question

I'm currently working on a Haskell project that uses lots of native code. This means that include files and libraries have to be accessible to cabal. I'm doing that by --extra-lib-dirs and --extra-include-dirs command-line flags.

I'm also using cabal sandboxes feature to avoid global dependency hell.

The trouble is that cabal often needs to reinstall some of my packages and thus rebuilds them, which requires native include files and libraries. So I have to specify --extra-lib-dirs and --extra-include-dirs at the command line when building any of my packages at all, even for those that don't require native code, which is very annoying.

I know I can use extra-lib-dirs and extra-include-dirs in .cabal files, but that ones don't allow relative paths and I prefer not committing files with absolute paths on my computer to a centralized repository.

So I wonder, is there any way to add directories to extra-lib-dirs or extra-include-dirs for all the packages in a sandbox? Or maybe globally for a computer?

Answer 1

You can simply create a local cabal.config in the directory where your sandbox is located. (Don't modify cabal.sandbox.config, as that file is auto-generated.)