k4-project-template

This repository can be a starting point and template for projects using the Key4hep software stack, in particular those writing Gaudi algorithms. To use it, instead of forking it, go to Github and click Use this template at the top right.

Dependencies

• ROOT

• PODIO

• Gaudi

• k4FWCore

This repository as a template

If you belong to the Key4hep organization, then it is possible to use this repository as a template for your new project, otherwise you can simply fork it and follow the next steps.

Compilation

Run, from the k4-project-template directory:

source /cvmfs/sw.hsf.org/key4hep/setup.sh
k4_local_repo
mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=../install -G Ninja
ninja install

Alternatively you can source the nightlies instead of the releases:

source /cvmfs/sw-nightlies.hsf.org/key4hep/setup.sh

Note that if you source the releases and use the current version of this repository this is not guaranteed to work as there could be changes since this repository was built for the release. What you can do in this case is to checkout a previous tag, for example:

git checkout v0.5.0

This is because the releases are only built with tagged versions of the packages. With the nightlies this repository should always work; if it doesn't please open an issue.

Execute Examples

Make sure that k4-project-template/install/lib and k4-project-template/install/python are in LD_LIBRARY_PATH and PYTHONPATH respectively (k4_local_repo should take care of this). If they are not, they can be added by running:

export LD_LIBRARY_PATH=$PWD/install/lib:$LD_LIBRARY_PATH
export PYTHONPATH=$PWD/install/python:$PYTHONPATH

and then run the examples like this:

k4run k4ProjectTemplate/options/createHelloWorld.py
k4run k4ProjectTemplate/options/createExampleEventData.py

Changing the name

Typically for a new project we would like to use a different name than k4ProjectTemplate. The change of names can be done quickly running these commands (change k4CoolProject to its name):

mv k4ProjectTemplate k4CoolProject
git ls-files | xargs sed -i 's/k4ProjectTemplate/k4CoolProject/g'

After this, your project should be ready to run

Continuous integration (CI) in forks

If this repository is forked instead of used as a template, CI will not work by default, because GitHub disables workflows by default in forks of foreign repositories. Workflows can be enabled by going to the Actions tab and clicking the green button labeled I understand my workflows, go ahead and enable them. If this is not done, no workflows will run, for example, after making a pull request. In addition, scheduled workflows are also disabled by default and require an additional step to be enabled manually from the Actions tab. The workflows that are disabled will have disabled next to them (at the time of writing, the only one is the Key4hep build).

References:

These could perhaps be usefule for newcomers.

1. lhcb-98-064 COMP
2. Hello World in the Gaudi Framework