Arch Linux is a rolling source-based distribution. It has an official package manager called 'pacman' and its extension 'yaourt' that installs community contributed software packages. The packages installed in this distribution are source-code based, which means that the distribution always gives access to the newest software versions. This can cause some problems when building and installing foam-extend, as for example PyFoam has been ported to Python 3 (see) but not been tested under working conditions.
2 Installing rpm-org
Install rpm-org, and remove rpm if you have it already installed.
yaourt -R rpm yaourt -S rpm-org
3 Installing and configuring virtualenv python virtual environment
yaourt -S python-setuptools
sudo easy_install virtualenv
Configure the python2.7 environment for foamext:
virtualenv -p python2.7 --no-site-packages ~/env/foamext
Source the python2.7 environment for foamext:
4 Building foam-extend
Once virtualenv and rpm-org are installed and virtualenv is activated as shown above, follow the tutorial that shows how to build foam-extend on Linux, the rest of the steps are exactly the same as shown there.