test for example & graphviz

there is currently no test exercising the pyconf/options/example.py and generally graphviz, which takes care of plotting the dataflow in case you EverythingHandler.plotDataFlow()

changed the description

shall we not move away from graphviz to pydot, which is actually available in lcg?

whatever is less PITA

Could you please add a slightly longer description of what is graphviz, why it matters, etc. ?

changed the description

@rmatev, please not that pydot is just a Python frontend, while the actual heavy lifting is still done by graphviz.

@gligorov, see https://www.graphviz.org/, and it matters because it's the engine that draws the nice dependency graphs.

Is it reasonable/feasible that we request that dot be included in the next LCG release?

Why do you need it in an LCG release, it is already installed in CentOS7:

-bash-4.2$ which dot
/usr/bin/dot

That's true on lxplus, but not in the centos7 docker image we have

lb-docker-run --centos7 which dot
WARNING : using environment variable LHCBNIGHTLIES for nightlies_dir
********************************************************************************
*                         ---- LHCb Login v9r2p6 ----                          *
*    Building with gcc8 on centos7 x86_64 system (x86_64-centos7-gcc8-opt)     *
********************************************************************************
 --- LHCBPROJECTPATH is set to:
    /cvmfs/lhcb.cern.ch/lib/lhcb
    /cvmfs/lhcb.cern.ch/lib/lcg/releases
    /cvmfs/lhcb.cern.ch/lib/lcg/app/releases
    /cvmfs/lhcb.cern.ch/lib/lcg/external
--------------------------------------------------------------------------------
which: no dot in (/cvmfs/lhcb.cern.ch/lib/lhcb/LBSCRIPTS/LBSCRIPTS_v9r2p6/InstallArea/scripts:/cvmfs/lhcb.cern.ch/lib/lcg/releases/LCG_95/Python/2.7.15/x86_64-centos7-gcc8-opt/bin:/cvmfs/lhcb.cern.ch/lib/lhcb/COMPAT/COMPAT_v1r19/CompatSys/x86_64-centos7-gcc8-opt/bin:/cvmfs/lhcb.cern.ch/lib/contrib/gdb/7.11/x86_64-slc6-gcc49-opt/bin:/cvmfs/lhcb.cern.ch/lib/contrib/ninja/1.4.0/x86_64-slc6:/cvmfs/lhcb.cern.ch/lib/contrib/glimpse/1.0.0/Linux-x86_64/bin:/cvmfs/lhcb.cern.ch/lib/contrib/CMake/3.11.0/Linux-x86_64/bin:/cvmfs/lhcb.cern.ch/lib/contrib/CMT/v1r20p20090520/Linux-x86_64:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/cvmfs/lhcb.cern.ch/lib/contrib/git/2.14.2/bin)

We could of course add it there if that's preferred.

Please discuss with @bcouturi

thanks for the pointer @clemenci !

mentioned in commit 087def22

mentioned in merge request !225 (merged)

mentioned in commit c6e3be02

closed via merge request !225 (merged)

mentioned in commit 465ac849

mentioned in commit LHCb@6c9511b2