Manages Cabal sandboxes to avoid rebuilding packages.

sandman aims to reduce the amount of time spent rebuilding commonly used Hackage packages by managing a global set of Cabal sandboxes that can be mixed into any project's Cabal sandbox.

For more information, check the README.

sandman helps manage Cabal sandboxes so that you can avoid rebuilding packages that you use often.

It does so by managing a global collection of sandboxes that were built separately. You can mix any number of these sandboxes into the package database for your project-specific sandbox.

Usage: sandman COMMAND

Available options:
  -h,--help                Show this help text

Available commands:
  list                     List sandman sandboxes or the packages in them
  new                      Create a new sandman sandbox
  destroy                  Delete a sandman sandbox
  install                  Install a new package
  mix                      Mix a sandman sandbox into the current project
  clean                    Remove all mixed sandboxes from the current project

Example usage

First, we create a sandbox that will contain packages we commonly use for development.

$ sandman list
lens (25 packages)

$ sandman new common
[..]
Created sandbox common.

Managed sandboxes can be told to use specific versions of GHC. This information will be propagated to projects with which this sandbox is mixed.

$ sandman new common --with-ghc ghc-7.6.3

We install our commonly used packages

$ sandman install common classy-prelude 
[..]
Configuring classy-prelude-0.10.2...
Building classy-prelude-0.10.2...
Installed classy-prelude-0.10.2

$ sandman list
lens (25 packages)
common (45 packages)

$ sandman list common
[..]
classy-prelude-0.10.2
[..]

$ sandman destroy lens
Removed sandbox lens.

$ sandman list
common (45 packages)

$ sandman install common optparse-applicative aeson

Next, we mix it into an existing project.

$ cd my_project
$ cabal sandbox init
$ cabal sandbox hc-pkg list | grep classy-prelude
<nothing>

$ sandman mix common
Mixing 45 new packages into package DB at [..]
Rebuilding package cache.

$ cabal sandbox hc-pkg list | grep classy-prelude
  classy-prelude-0.10.2

$ cabal repl
GHCi, version 7.8.3: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
λ> import ClassyPrelude
λ> 

$ sandman clean
Removing all mixed sandboxes.
Removed 45 packages.
Rebuilding package cache.

sandman can also mix in only specific packages and their dependencies from managed sandboxes.

$ sandman mix common --only system-filepath --only system-fileio
Mixing 3 new packages into package DB at [..]
Rebuilding package cache.

$ cabal sandbox hc-pkg list
[..]
  system-fileio-0.3.16
  system-filepath-0.4.13.1
  text-1.2.0.4

The --executables option may be used to include executables from a sandbox.

$ sandman mix common --executables --only hspec
Mixing 15 new packages into package DB at [..]
Rebuilding package cache.

$ ls .cabal-sandbox/bin
hspec-discover

Stack

sandman also supports mixing in packages from a stack snapshot package database.

$ sandman mix stack

This mixes in all packages from the default snapshot database into the current Cabal sandbox. The -o/--only options may be used to limit the packages to a minimal subset.

$ sandman mix stack -o text

Status

Sandman is stable enough for basic use cases but there are surely a lot of unexplored corner cases. Feel free to try it out. Keep in mind that since you're breaking sandbox boundaries, there is a higher chance of running into version conflicts.

Installation

You can download and install sandman from Hackage by using,

$ cabal install sandman

Or if you would rather not pollute your global package database, install it into a sandbox and copy the executable somewhere on your $PATH.

$ mkdir tmp && cd tmp
$ cabal sandbox init
$ cabal install sandman
$ cp .cabal-sandbox/bin/sandman ~/bin

Or simply use stack:

$ stack install sandman