haskell-incremental-build-template

[!IMPORTANT]
This minimal template focuses solely on incremental Haskell build configuration with Nix.
For a more batteries-included Haskell Nix template, combine it with

[!IMPORTANT]
Requires GHC >= 9.4

A template for incremental Haskell builds using Nix, leveraging nixpkgs’s Haskell incremental build system and [haskell-flake]

Getting Started

For an existing Haskell project already using [haskell-flake], integrate this template by:

• Add the prev flake input (see flake.nix).

https://github.com/juspay/haskell-incremental-build-template/blob/7432331400f27924d827fbf81de5140c1fa0052c/flake.nix#L10-L14

• Include settings from haskell.nix:

https://github.com/juspay/haskell-incremental-build-template/blob/7432331400f27924d827fbf81de5140c1fa0052c/nix/modules/flake/haskell.nix#L20-L32

• Use Find Latest Cached Commit action to find the commit hash with cached build artifacts.

https://github.com/juspay/haskell-incremental-build-template/blob/efd179a97b078634db3f124e862260d3acc35499/.github/workflows/ci.yaml#L30-L48

Quick Trial

• Clone the repository: git clone https://github.com/juspay/haskell-incremental-build-template && cd haskell-incremental-build-template
• Perform a full build: nix build .#default -L

• This builds both Example.hs and Main.hs modules.
• Add a newline to Main.hs to simulate a change: echo >> src/Main.hs
• Perform an incremental build: nix build .#default --override-input prev github:juspay/haskell-incremental-build-template -L

• Only Main.hs is rebuilt.