Geant4 10.4 compatibility

[petricm]

The following tests fail when compiling against Geant4 10.4

The following tests FAILED:
	 14 - t_CLICSiD_DDG4_CLICSiDAClick_as_AClick_LONGTEST (Failed)
	 28 - t_LHeD_DDG4_LHeDACLick_as_ACLick_LONGTEST (Failed)

with the message:

14/202 Test  #14: t_CLICSiD_DDG4_CLICSiDAClick_as_AClick_LONGTEST ...............***Failed  Error regular expression found in output. Regex=[Error]  2.67 sec
 ### running test :  'root.exe  -b -x -n -q -l /Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/DDG4/examples/run.C("/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/CLICSiD/scripts/CLICSiDAClick")'

Processing /Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/DDG4/examples/run.C("/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/CLICSiD/scripts/CLICSiDAClick")...
Status(.L /Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/DDG4/examples/initAClick.C+) = 0
+++ Includes:   -I$ROOTSYS/include  -I/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/DDG4/examples -I/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep -I/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/include -I/cvmfs/clicdp.cern.ch/software/Geant4/10.04/x86_64-mac1013-llvm90-opt/include/Geant4 -Wno-shadow -g -O0 -I"/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/include" -I"/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/include" -I"/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/include" -I"/cvmfs/clicdp.cern.ch/software/ROOT/6.12.06/x86_64-mac1013-llvm90-opt/etc" -I"/cvmfs/clicdp.cern.ch/software/ROOT/6.12.06/x86_64-mac1013-llvm90-opt/etc/cling" -I"/cvmfs/clicdp.cern.ch/software/ROOT/6.12.06/x86_64-mac1013-llvm90-opt/include" -I"/usr/include" -I"/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/build/CLICSiD/"
+++ Linked libs:-L$ROOTSYS/lib -lCore -lRint   -L/cvmfs/clicdp.cern.ch/software/ROOT/6.12.06/x86_64-mac1013-llvm90-opt/lib -L/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/lib -lDDCore -lDDG4 -L/cvmfs/clicdp.cern.ch/software/Geant4/10.04/x86_64-mac1013-llvm90-opt/lib
Info in <TMacOSXSystem::ACLiC>: creating shared library /Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/CLICSiD/scripts/CLICSiDAClick_C.so
In file included from input_line_12:9:
/Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/CLICSiD/scripts/CLICSiDAClick.C:24:10: fatal error: 'CLHEP/Units/SystemOfUnits.h' file not found
#include "CLHEP/Units/SystemOfUnits.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Error in <ACLiC>: Dictionary generation failed!
(int) 0
Status(.L /Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/DDG4/examples/initAClick.C+) = 0
+++ Status(.X /Users/gitlab-runner/builds/98de57ac/0/mpetric/DD4hep/examples/CLICSiD/scripts/CLICSiDAClick.C+()) = 0

It appears it does not find CLHEP, adding to USES of the target CLHEP e.g.

dd4hep_add_executable(CLICSiDAClick SOURCES scripts/CLICSiDAClick.C
USES [DD4hep REQUIRED COMPONENTS DDCore DDG4] Geant4 CLHEP)

does not mitigate the problem. Apparently the propagation of CLHEP information from Geant4 has changed again.

[MarkusFrankATcernch]

Is this a "new" version of Geant4 Marko?
I did a merge yesterday, but this area I did not touch at all.

[petricm]

Yes, Geant4 10.4 was released December, we are presently testing in the CI 10.3.3 and 10.2.3 and I tried out the new one.

The complete output can be seen here, the failed jobs are from 10.4 the passed ones are from 10.3 and 10.2.

The necessary changes for the CI scripts are in this branch

[petricm]

The problem is in Geant4Config.cmake:
Geant4 10.2 and 10.3 set this variable

set(CLHEP_ROOT_DIR "/some_path/CLHEP/2.3.4.3/x86_64-slc6-gcc7-opt")

whereas Geant4 10.4 sets this variable

set(CLHEP_DIR "/some_path/CLHEP/2.4.0.0/x86_64-slc6-gcc7-opt/lib/CLHEP-2.4.0.0")

searching for a common solution

[petricm]

Follow up with Geant4 https://bugzilla-geant4.kek.jp/show_bug.cgi?id=2050

[petricm]

FYI, response from Geant4

This is due to the change from using our own "FindCLHEP" module to the use of
CLHEP's provided "CLHEPConfig.cmake" file. The later is now, and will be, the
way in which CLHEP is located and configured.

CLHEP_ROOT_DIR won't be supported going forward and it's not a standard
variable, and may not be reliable in all cases (it's highly dependent on how
the client packaged/installed CLHEP).