If the gtools you need is not on Hackage, it might be a private or legacy package. In that case, you鈥檒l need to use cabal in a different way (e.g., pointing to a Git repo). The gtools cabal download command is not a standalone command. Instead, you use cabal to download, build, and install the package. Here鈥檚 what you need first: 1. Install GHC (Glasgow Haskell Compiler) # On Ubuntu/Debian sudo apt install ghc On macOS (using Homebrew) brew install ghc On Windows (using Chocolatey) choco install ghc 2. Install Cabal (the build tool) # Using your distro's package manager (often outdated) sudo apt install cabal-install Recommended: Use ghcup (Haskell toolchain manager) curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh ghcup install cabal latest
mkdir my-project && cd my-project cabal init cabal install --lib gtools --package-env . Error 1: "Unknown package: gtools" Cause: The package does not exist on Hackage, or you misspelled it (e.g., gtool , g-tools ). Fix: Verify the exact name: gtools cabal download
# Ubuntu/Debian sudo apt install libgsl-dev libblas-dev brew install gsl Error 4: "cabal: Could not resolve dependencies" This is a version conflict. Use a fresh cabal project with a cabal.project file: If the gtools you need is not on
