## Motivation A problem when building large amounts of dependencies with stack or cabal is that we don't get to exploit any module level parallelism due to cabal using `--make` mode without any `-j` flags. It is sensible to not pass any `-j`: cabal-install uses the parallelism between packages too so it isn't easy choosing how many threads to allow. ## Proposal Have some feature like the GNU make jobserver in GHC. GNU make documentation: https://www.gnu.org/software/make/manual/html_node/Job-Slots.html ## Notes rust's `cargo` is both a jobserver client and a jobserver server since https://github.com/rust-lang/cargo/pull/4110 Ocaml decided the jobserver protocol was too hairy: https://github.com/ocaml/dune/pull/4331