Stack

Stack is a Haskell project workflow CLI that combines toolchain setup, dependency resolution, builds, and project commands around a stack.yaml snapshot. It is built for reproducible local development and CI in Haskell codebases rather than general system package management.

• Create or initialize Haskell projects, pin them to a snapshot, and install the GHC version and supporting tools they need.
• Build, test, benchmark, document, and run project packages or selected components from one CLI.
• Inspect dependency sets, build paths, and project metadata for debugging, environment setup, or follow-up automation.

• Most commands are non-interactive and project-scoped, which makes Stack workable in CI and agent loops for build, test, run, and environment setup.
• Structured output exists but is narrow: stack ls dependencies json emits JSON and stack query emits YAML, while much of the rest of the surface is text-first.
• Best fit when an agent already has a checked-out Haskell project and needs to validate builds, run executables, or inspect the Stack environment.

• First runs can download GHC, package indexes, or MSYS2, so automation is slower and more environment-sensitive than simpler language CLIs.
• The documented Homebrew formula is unofficial and can lag new releases; the direct installer or release binaries are the canonical paths.