Compiling on macOS using Homebrew

What is homebrew and why use it

To quote from their website:

Homebrew is the missing package manager for OS X:

• easy to install
• does not need administrator privileges
• installs packages to their own directory and then symlinks their files into /usr/local

For further information to install it and how to use it, see the Homebrew website and the Wiki.

The formulas to install programs are called recipes and they make it possible to install several version of the same program (as well as HEAD of different Version Control Systems) at the same time which can then be symlinked. This makes it perfect for the purpose of installing the master branch of GRASS GIS for testing purposes.

GRASS GIS 7.6+

There is an osgeo4mac which contains recipes for GRASS GIS 7.x and other GIS tools - highly recommendable tap!

Installation:

Just run

     brew tap osgeo/osgeo4mac

and then

     brew install osgeo-grass.rb

Easy, isn't it?

You can also install via URL:

     brew install https://github.com/OSGeo/homebrew-osgeo4mac/blob/master/Formula/osgeo-grass.rb

Testing:

• by running (change '7x' to the current version)

     brew test -v grass-7x

you can run GRASS GIS tests but they are not implemented as they should be - work in progress.

GRASS GIS 7.2

If you have a 3rd party Python installed, and/or Python 3, you need to remove it from your path for the installation. Once installed, GRASS will run even if the primary Python is, for example, Anaconda Python 3.

Display the current path, and remove any folders or directories that provide access to the non-system python2.7:

   echo $PATH
   #  ~/local/anaconda/bin:/Users/MyName/bin:/usr/local/bin:/usr/bin/sbin

Reset path

   PATH=/usr/local/bin:/usr/bin/sbin

Set GRASS python

   export GRASS_PYTHON=/System/Library/Frameworks/Python.framework/Versions/Current/bin/pythonw

Install packages with Brew

   brew tap osgeo/osgeo4mac
   brew install netcdf
   brew install gdal2 --with-complete --with-unsupported
   export GDAL_DATA=/usr/local/opt/gdal2/share/gdal/   
   # Also add the above line to ~/.bash_profile, ~/.bashrc, or some other login script
   brew install grass7 --with-netcdf
   brew install gdal2-grass7

Notes:

1. PATH adjustments are only needed during installation. After installation, the PATH can return to its default value and GRASS works fine.
2. There may be other brew dependencies that were installed previously and therefore not listed here.

How to install GRASS GIS 7.1 SVN Head

I assume that homebrew is installed and working.

Different recipes are organized in so called taps which need to be added to homebrew by using brew tap command. The GRASS GIS 7.1 recipes are in the following github repo:

https://github.com/rkrug/homebrew-head-only

In addition, GRASS GIS has dependencies which can be found in the homebrew/science tap.

To add these two to homebrew, one has to use the commands

     brew tap rkrug/head-only  
     brew tap homebrew/science
     brew update

If you want to use the option --with-liblas make sure that liblas is build using the correct installed version of gdal by running

     brew install liblas
     brew install --build-from-source liblas

The first comand installs from bottles (binary) when available, and the second command reinstalls liblas by building it from source, therby using installed dependencies.

Otherwise you might get the following error when using the option --with-liblas:

     checking whether to use libLAS... yes
     checking for liblas-config... /usr/local/opt/liblas/bin/liblas-config
     configure: error: *** Unable to locate libLAS library.

Thanks to Glynn Clements for identifying this error (see the mail on gmane).

Finally, GRASS 7.1 SVN can be installed by

     brew install --HEAD grass-71

This should be it.

If this does not work, please leave comments at the issues page of the tap or at the grass-dev mailing list.

GRASS GIS 7.0.x for El Capitan without disabling SIP

The new homebrew recipe for GRASS 7.0 does install on El Capitan with SIP enabled! This is thanks to Larry Shaffer. See https://github.com/OSGeo/homebrew-osgeo4mac/issues/118#issuecomment-200278686

The recipe is part of the Homebrew-osgeo4mac tap, see

https://github.com/OSGeo/homebrew-osgeo4mac

for info on how to use them.