How to build and use Gaudi with CMake

Requirements

The CMake configuration of Gaudi is based on the version 3.15.0 or later of CMake. On lxplus (SLC6 and CentOS7) you need to call something like:

$ export PATH=/cvmfs/sft.cern.ch/lcg/contrib/CMake/3.18.3/Linux-x86_64/bin:$PATH

Quick Start

Gaudi requires some uncommon external libraries, so the quickest way to build it is to use the CERN SFT provided LCG views, for example:

. /cvmfs/sft.cern.ch/lcg/views/LCG_97a/x86_64-centos7-gcc9-opt/setup.sh

Note that the version of CMake in LCG_97a view is too old, so one had to add:

export PATH=/cvmfs/sft.cern.ch/lcg/contrib/CMake/3.18.3/Linux-x86_64/bin:$PATH

We suggest the use of Ninja to build, if you wish to do so, you can use these settings:

export PATH=/cvmfs/sft.cern.ch/lcg/contrib/ninja/1.10.0/Linux-x86_64:$PATH
export CMAKE_GENERATOR=Ninja

At this point the environment is good enough to use a standard CMake procedure:

cd Gaudi
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DGAUDI_USE_PYTHON_MAJOR=$(python -c "import sys; print(sys.version_info[0])")

The special option -DGAUDI_USE_PYTHON_MAJOR is needed with LCG versions less than 99, where the default version of Python is 2, while Gaudi looks for 3 by default.

Run from the build directory

For testing and debugging there is no need to install, but Gaudi requires some environment variables to be set, so the build procedure generates a special script (build/run) that can be used to run a command in the correct environment, for example:

build/run gaudirun.py --help

or

build/run bash

to have a shell with the correct environment.

Testing

Gaudi comes with a pool of tests (built by default, unless one passes the option -DBUILD_TESTING=FALSE to Gaudi) that can be run with ctest:

cd build
ctest

Resources

• CMake documentation
• FindTBB.cmake was taken from https://bitbucket.org/sergiu/tbb-cmake And should be removed in a near future.