I have a use case for running some random IO action just before each component is built. It is important that my action is run interleaved with the build itself, since the IO action for a component may require the build artifacts of other components that are earlier in the dependency list. The IO action returns an edited BuildInfo, which is then passed to the normal build hook.

I have a prototype implementation at https://github.com/gergoerdi/clashilator/blob/c2561e8465ba235aa4836e3bfae35f84fa578d26/src/Clash/Clashilator/Cabal.hs. I'm not too happy with how deeply it has to fiddle with Cabal internals, so it would be better if this, or something similar to this, was exposed via the Cabal API.