1. Building and Installing Gaudi¶

1.1. Introduction¶

Gaudi uses the CMake cross-platform build-generator tool as a build system. CMake does not build the project, it generates the files needed by your build tool (GNU make, Ninja, Visual Studio, etc.) for building Gaudi. Before attempting the build you need to have installed a number of mandatory prerequisites external packages on which Gaudi depends. Check the pre-requisites and supported platforms for the list of packages that will needed to install and setup before you starting the build. If your platform is one of the common platforms used by the HEP coummunity very likely all the required packages will be available in CVMFS, alternatively your can install them locally, for example using the lcgcmake packaging tool, or one of the alternative tools.

1.2. Using the externals from CVMFS¶

If your system has CVMFS installed, the simplest is to setup a build environment using the LCG views. This is done by executing

source /cvmfs/sft.cern.ch/lcg/views/setupViews.sh <lcg-version> <platform-tag>

The list of available LCG versions with their content and availale platforms can be browsed at the lcginfo site. You can also use the latest build of the stack of externals using the lcg version dev4/latest or dev3/latest. For example:

source /cvmfs/sft.cern.ch/lcg/views/setupViews.sh dev4/latest x86_64-centos7-gcc8-opt

1.3. Installing the externals locally¶

Alternatively you can install all the required external dependencies locally in your system. An easy way to achive this is to use the lcgcmake tool. The following are the basic instructions to install all the required packages for Gaudi in a <prefix> location.

Install lcgcmake by just cloning the lcgcmake package and ensure that the PATH environment variable contains the the bin directory
```
git clone https://gitlab.cern.ch/sft/lcgcmake.git
export PATH=$PWD/lcgcmake/bin:$PATH
```

Configure the software stack by selecting the compiler

mkdir tmp; cd tmp
lcgcmake configure --compiler=gcc8 --prefix=<prefix>

Install all the required packages. The target GAUDI-externals can be used to ease the job
```
lcgcmake install GAUDI-externals
```

Setup the environment with the constructed local view

source <prefix>/hsf/x86_64-centos7-gcc8-opt/setup.sh

1.4. Building Gaudi¶

Gaudi builds as any CMake based project. Once the externals packages are installed or accessible it is as simple as running the configuration with the command cmake <options> on a build area and to execute cmake --build.

git clone https://gitlab.cern.ch/gaudi/Gaudi.git
mkdir build; cd build
cmake ../Gaudi -DBoost_NO_BOOST_CMAKE=TRUE
cmake --build . [ -- -j8]

# for running all the builtin tests
ctest -j8

1.5. Running some examples¶

The examples can be run using the command run available in the buiold directory.

./run gaudirun.py --help
./run gaudirun.py Histograms.py
./run gaudirun.oy FunctionalAlgorithms/ProduceConsume.py

To start a shell with all the running environment start the bash executable

./run bash

1.6. Pre-requisites¶

This table lists the external dependencies of Gaudi. The ones marked as mandatory are the only ones essencial for building and running simple tests or examples.

Package	Version	Mandatory
ROOT	>= 6.16	yes
Python	>= 2.7	yes
Boost	>= 1.67	yes
TBB		yes
LibLZMA		yes
uuid		yes
VDT		yes
AIDA		no, needed for RootHistCnv
XercesC		no, used for the XML file catalogue
CppUnit		no
HepPDT		no
CLHEP		no
OpenCL		no
unwind		no
gperftools		no
jemalloc		no
Rangev3		no, needed with option GAUDI_USE_SYSTEM_RANGES_V3
Doxygen		no, needed to generate documentation
cppgsl		no, needed with option GAUDI_USE_SYSTEM_CPP_GSL
zlib		no, needed for the profiling tools

1.7. Supported platforms¶

CentOS 7 with gcc 8
SCL 6
Ubuntu 18.04
MacOS 10.14 with Xcode (experimental)