Bug 407517 – sci-physics/geant:4: configuration issues

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Marek Szuba (RETIRED) 2012-03-09 11:45:15 UTC]

Hello,

There are several issues in Gentoo ebuilds of Geant4 which might be worth addressing. Most of these should in principle apply to all versions of Geant4 which we build using CMake, however here I will concentrate on version 4.9.5 as it is the first one in which there is no alternative. Moreover, I am perfectly aware of the fact many of these issues stem from upstream shortcomings... Still, it would be good to have things under control - or maybe even submit the necessary corrections upstream.

1. To begin with, something simple: the line checking USE=dawn is duplicated.

2. Next, a clear-cut bug: the option passed to CMake when USE=geant3 is set should be GEANT4_USE_G3TOG4, not GEANT4_USE_GEANT3TOGEANT4.

3. On a related note, although Geant4 documentation (which our ebuilds follow in this respect) says simply "set this option to enable GEANT3 support, you will need CERNLIB and a Fortran compiler", in reality there are in fact TWO levels of this support:
 - building libG3toG4, a library containing e.g. code for unit conversion between GEANT3 and Geant4,
 - building the tool for converting GEANT3 geometry to Geant4 format.
Whereas the latter does require CERNLIB and a Fortran compiler, if you just want the former it is enough to set GEANT4_USE_G3TOG4. It is worth mentioning at this point that there ARE applications which can require this library alone - the Geant4 back-end for the Virtual Monte Carlo (VMC) interface, for instance.
My point here is, maybe it makes sense to split USE=geant3 into two separate flags, one for the geometry converter (with all the pesky dependencies) and one for the compatibility library?

4. USE=dawn and USE=vrml do not do what one might expect: instead of just switching respective visualisation drivers on, they enable their support for over-the-network communication. Then again, having these flags off does seem to disable respective drivers (at least the VRML one anyway - haven't tried what would happen if I used USE=-dawn with DAWN installed) so fixing this may not be worth it.

5. The environment scripts upstream Geant-4.9.5 installs in bin (geant4.sh and geant4.csh) are presently useless in the case of ebuild-driven installation - on one hand with everything installed in /usr their modifications of PATH and LD_LIBRARY_PATH serve no purpose, on the other they do not specify the location of data files (without which certain things do not work at all since this version) because CMake scripts not knowing how to handle data files yet. I would suggest:
 - with USE=data set, replacing these two with our custom versions pointing to correct subdirectories of /usr/share/geant4/data,
 - otherwise, not installing them at all

[Comment 1 Sébastien Fabbro (RETIRED) 2012-03-13 21:54:32 UTC]

+*geant-4.9.5-r1 (13 Mar 2012)
+
+  13 Mar 2012; Sébastien Fabbro <[e-mail]>
+  files/geant-4.9.4-zlib.patch, +geant-4.9.5-r1.ebuild:
+  Fixed more zlib issues. The geant3 flag is now only for unit conversion (if
+  geant3 is needed, geant:3 has to be installed from user). The data is now
+  fetched (building needs network) to ease maintenance and set up the proper
+  env variables in the geant4*sh scripts. Removed a use dawn duplicate. Thanks
+  Marek Szuba for his suggestions (bug #407517 and bug #359673). Added a
+  message for backward compatibility (bug #360285)
+

Re-open if you still see issues.
Thanks.