Cabal

Working with sandboxes

A Haskell project can either use the system wide packages or use a sandbox. A sandbox is an isolated package database and can prevent dependency conflicts, e. g. if multiple Haskell projects use different versions of a package.

To initialize a sandbox for a Haskell package go to its directory and run:

cabal sandbox init

Now packages can be installed by simply running cabal install.

Listing packages in a sandbox:

cabal sandbox hc-pkg list

Deleting a sandbox:

cabal sandbox delete

Add local dependency:

cabal sandbox add-source /path/to/dependency

Install packages

To install a new package, e.g. aeson:

cabal install aeson

Syntax

• cabal where is one of:

**[global]**

• update
  - Updates list of known packages

  • Install packages

  • Help about commands

  • Display detailed information about a particular package

  • List packages matching a search string

  • Downloads packages for later installation

  • Display and update the user’s global cabal configuration

  • get
    - Download/Extract a package's source code (repository)

    • Create a new .cabal package file (interactively)

    • Prepare to build the package

    • Compile all/specific components

    • Clean up after a build

    • Builds and runs an executable

    • Open an interpreter session for the given component

    • Run all/specific tests in the test suite

    • Run all/specific benchmarks

    • Check the package for common mistakes

    • Generate a source distribution file (.tar.gz)

    • Uploads source packages or documentation to Hackage

    • Upload build reports to a remote server

    • Freeze dependencies

    • Generate dependency bounds

    • Generate Haddock HTML documentation

    • Generate HsColour colourised code, in HTML format

    • Copy the files into the install locations

    • Register this package with the compiler

    • sandbox
      • Create/modify/delete a sandbox
        - cabal sandbox init [FLAGS] - cabal sandbox delete [FLAGS] - cabal sandbox add-source [FLAGS] PATHS - cabal sandbox delete-source [FLAGS] PATHS - cabal sandbox list-sources [FLAGS] - cabal sandbox hc-pkg [FLAGS] [--] COMMAND [--] [ARGS]

        • Give a command access to the sandbox package repository

        • Open interpreter with access to sandbox packages