Installing OR-Tools .Net from Source on MacOS

Introduction

This guide explains how to install OR-Tools from source, with support for .Net, on MacOS. Unless you plan to modify the source code or use a third-party solver with OR-Tools, we recommend the binary installation.

Although these instructions might also work on other MacOS variants, we have only tested them on machines meeting the following requirements:

MacOS 10.15.2 (Catalina) 64-bit (x86_64)

Prerequisites

The following sections describe the prerequisites for installing OR-Tools from source.

Xcode Command Line Tools

You must install the Xcode Command Line Tools. To do so, open the Terminal, found in /Applications/Utilities/, and enter:

xcode-select --install

Click “Install” to download and install Xcode Command Line Tools. You don’t need to "Get Xcode" from the App Store. If you have a slow Internet connection, it may take many minutes.

Verify that you’ve successfully installed Xcode Command Line Tools:

xcode-select -p

You should see:

/Applications/Xcode.app/Contents/Developer

Homebrew

To install the remaining prerequisites, we recommend first installing the "missing package manager for macOS" otherwise known as Homebrew. To do so, open a terminal window and enter:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
brew update

To verify that you’ve successfully installed brew:

brew --version

You should see:

Homebrew 1.6.9-8-g25542d7
Homebrew/homebrew-core (git revision 0e0c84; last commit 2018-06-20)

C++ tools

To install C++ tools, open a terminal window and enter:

brew install cmake wget pkg-config

SWIG tool

To install SWIG tool, open a terminal window and enter:

brew install swig

.Net tools

To install .Net tools, open a terminal window and enter:

brew cask install dotnet-sdk

Download the source code

There are two distinct branches of the OR-Tools source code on GitHub: stable and master. The stable branch has been thoroughly tested and should work flawlessly on all supported platforms. The master branch is where the latest updates and improvements have been applied; it's more current, but less stable.

Download the stable source code

You can get the stable source code for OR-Tools in either of the following ways:

Clone the stable branch by entering

git clone https://github.com/google/or-tools

Download the latest release in a compressed file, by clicking the Clone or download button in GitHub.

Download the master source code

To retrieve the source code from the master branch, enter

git clone -b master https://github.com/google/or-tools

Download previous releases

You can get the source code for previous releases in either of the following ways:

Download a previous release from the GitHub release page.
Assuming you have already created a local repository (by git clone), you can check out a specific release using a Git tag. For example, to work with the v7.6 release instead of the master branch, enter the following commands in your local repo:
```
git fetch --all --tags --prune
```
```
git checkout tags/v7.5 -b v7.5
```

Build the source code

To build the source code:

Open a terminal and navigate to the directory where you extracted the files. Then enter the following command:
```
make third_party
```
To use a third party solver, open Makefile.local in the main or-tools directory, and add the path to the directory where you installed the solver. For example, for SCIP you would add this:
```
UNIX_SCIP_DIR=scip/install/dir
```
Compile OR-Tools by entering
```
make dotnet
```
You can check that everything is running correctly by entering
```
make test_dotnet
```

This runs a selection of examples for OR-Tools. If all the examples run successfully, you are ready to get started with OR-Tools.

Using a third-party solver

You can use OR-Tools with any of the following third-party solvers:

If you have already installed OR-Tools and want to configure it to use one of these solvers, do the following steps:

Open a terminal and navigate to the or-tools directory. Then enter the following command:
```
make third_party
```
Open Makefile.local and add the path to the directory where you installed the solver. For example, for SCIP you would add this:
```
UNIX_SCIP_DIR=scip/install/dir
```
Compile OR-Tools by entering
```
make clean
```
```
make all
```

Install the SCIP Optimization Suite

To install the SCIP Optimization Suite on a Mac, do the following steps:

Download the SCIP archive and unpack it.

Navigate to the top level of the unpacked archive and enter the following commands:

make GMP=false READLINE=false TPI=tny ZIMPL=false PARASCIP=true scipoptlib install INSTALLDIR=/scip/install/dir
make
make install

After the installation is complete, follow the instructions in Using a third-party solver.

Cleaning the build files

If you need to re-install OR-Tools, the command:

make clean_third_party

will remove all compiled dependencies and Makefile.local. This can be useful for resetting to a clean state.

Then re-enter the commands

make third_party

make dotnet