# Prerequisites for building on OS X

Build prerequisites for OS X should be installed automatically as part of the build process.
This is done by a helper script [`fetch-build-deps.sh`](/project/victor/scripts/fetch-build-deps.sh).

## Mac OS X

We currently support building on Mac OS 10.12. Older versions may also work,
but we do not actively support them. If you run into problems trying to build
on old versions of MacOS, your options are to figure it out or upgrade.

## Mac build environment

We use the clang compiler toolchain bundled with Xcode in order to build mac
binaries for tests and webots simulations. Production builds are currently
using Xcode 9.1.

You can install Xcode from the Mac App Store. Make sure you open XCode at least
once after installing / updating because it may ask you to accept terms of
service before it can be run from build scripts.

## Homebrew

If you don't already have [brew](http://brew.sh), get it now:

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

Then use brew to install the following dependencies. Note that Apple's included
Python can cause problems, so it's recommended to install through brew:

``` bash
brew install python3
brew install python@2
```

You will also need to install the python yaml module, `pyyaml`, for both python2
and python3:

``` bash
pip2 install pyyaml
pip3 install pyyaml
```

Once the tools are installed, you can setup your shell environment for Vicos
development by running the command:

``` bash
source project/victor/envsetup.sh
```