DepSelectorLibgecode

This library vendors Gecode 3.7.3 as a rubygem so it can easily be used with the dep-selector project.

Gecode is a fast CSP solver library written in C++. We created this library to install it in order to optimize the following criteria:

Allow users to install libraries that depend on gecode without extra steps.
Install the correct version of gecode for dep-selector. The current release line of gecode is 4.x, but dep-selector uses ~> 3.5.
Configure the source installation for shortest compilation time by excluding unnecessary components. Gecode has a reputation for taking a long time to compile, but in fact most of that time is spent building examples and documentation. We've disabled these, along with the flatzinc interpreter.

Installation

Add this line to your application's Gemfile:

gem 'dep-selector-libgecode'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dep-selector-libgecode

Installation on Windows

The recommended installation method is ChefDK and the following steps can be skipped if you choose this method.
Don't set USE_SYSTEM_GECODE to anything. The build only checks for the presence of this variable, not the value.
Install ruby. Install DevKit(preferred), or install mingw and add it to your PATH. You can use the Chef omnibus MSI to get a working ruby and devkit.
Install a working tar, and include it in your PATH. There is a tar binary that comes with the git package, but it is horribly broken and only good for generating core dumps. Before you build anything check where tar to make sure the tar from git is not the first one in your PATH. The chef-client omnibus package has a tar that works (easiest), or you can get one from here: http://gnuwin32.sourceforge.net/packages/gtar.htm
gem install berkshelf should work now.
Examples for automating these builds can also be found at omnibus-chef and omnibus-software.

Requirements

This gem runs make with concurrent jobs to speed build time, so it uses about 2GB of RAM during the build. If this doesn't work for your environment, see 'Using a System Gecode Instead' below. Better yet, if you only want to install Berkshelf, try using ChefDK instead of a gem install.

Using a System Gecode Instead

Use the "USE_SYSTEM_GECODE" environment variable when installing to make dep-selector-libgecode use the system version, instead of downloading the source and building its own copy:

$ USE_SYSTEM_GECODE=1 gem install dep-selector-libgecode

WARNING: Ensure that your system packages provide Gecode version 3 and not version 4. Version 4 does not work with dep-selector.

Usage

DepSelectorLibgecode provides helper functions for locating the vendored gecode after installation:

require 'dep-selector-libgecode'

# The vendored lib dir:
DepSelectorLibgecode.opt_path

# The include dir (where the headers are):
DepSelectorLibgecode.include_path

Vendoring Native Gems (docs for Maintainers)

The rake native command can be used to build a native "fat" gem.

It is recommended to use the following process:

% git clean -ffdx
% git checkout -- .
% rake native
% gem push pkg/dep-selector-libgecode-1.3.0-x86_64-darwin-15.gem  # obviously use the filename you actually built here

Without cleaning up the repo first and nuking stuff in ext/ and pkg/ the rake native command will fail.

Licensing

The packaging code here is released under the terms of the Apache2 license. Gecode itself is released under the terms of the MIT license.

See CONTRIBUTING.md for more information.

Contributing