Problem 777

Summary:	Use of HepMC version in conflict with version used by experiment framework
Product:	Geant4	Reporter:	gloria.corti
Component:	event	Assignee:	Makoto.Asai
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	gloria.corti
Priority:	P2
Version:	7.1
Hardware:	PC
OS:	Linux

Description gloria.corti 2005-08-02 04:42:30 CEST

In LHCb we use a version of HepMC as taken from the original author. In Geant4
the version used is tat of CLHEP where additional methods are defined. Such
methods are used in Geant4 code. Since we compile with the granular CLHEP
library when we build the full simulation application (Generators+Geant4) we
link only with the original HepMC: this give rise to undefined symbols.
We do not use the facility of Geant4 to read in HepMC directly, since we pass
ourselves the primary event, so we do not need this facility. It would be
useful to be able to switch off the use (i.e. compilation) of HepMC in Geant4,
this is already done when compiling on window where the WIN32 flag encapsulate
the use HepMC, turning it off.

Comment 1 asai 2005-09-28 11:23:59 CEST

When LHC requested the support of HepMC interface, it was agreed that we
would support it as long as HepMC is centrally and uniquely maintained by
CLHEP. Given it is not the case now, we should think about dropping HepMC
interface from our distribution. I will discuss this at the coming TSB.