DAGMC not compatible with Geant4 10.6

[ljacobson64]

There appear to have been some changes in Geant4 10.6 that break our ability to build Dag-Geant4 applications. Stuff like this appears during build:

/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc: In function ‘int main(int, char**)’:
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:84:5: error: ‘G4UIExecutive’ was not declared in this scope
   84 |     G4UIExecutive* ui = new G4UIExecutive(argc, argv, "tcsh");
      |     ^~~~~~~~~~~~~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:84:20: error: ‘ui’ was not declared in this scope
   84 |     G4UIExecutive* ui = new G4UIExecutive(argc, argv, "tcsh");
      |                    ^~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:84:29: error: expected type-specifier before ‘G4UIExecutive’
   84 |     G4UIExecutive* ui = new G4UIExecutive(argc, argv, "tcsh");
      |                             ^~~~~~~~~~~~~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:87:12: error: type ‘<type error>’ argument given to ‘delete’, expected pointer
   87 |     delete ui;
      |            ^~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:89:5: error: ‘G4VisManager’ was not declared in this scope; did you mean ‘G4VPCManager’?
   89 |     G4VisManager* visManager = new G4VisExecutive;
      |     ^~~~~~~~~~~~
      |     G4VPCManager
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:89:19: error: ‘visManager’ was not declared in this scope; did you mean ‘scManager’?
   89 |     G4VisManager* visManager = new G4VisExecutive;
      |                   ^~~~~~~~~~
      |                   scManager
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:89:36: error: ‘G4VisExecutive’ does not name a type
   89 |     G4VisManager* visManager = new G4VisExecutive;
      |                                    ^~~~~~~~~~~~~~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:92:5: error: ‘G4UIExecutive’ was not declared in this scope
   92 |     G4UIExecutive* UI = new G4UIExecutive(argc, argv);
      |     ^~~~~~~~~~~~~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:92:20: error: ‘UI’ was not declared in this scope
   92 |     G4UIExecutive* UI = new G4UIExecutive(argc, argv);
      |                    ^~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:92:29: error: expected type-specifier before ‘G4UIExecutive’
   92 |     G4UIExecutive* UI = new G4UIExecutive(argc, argv);
      |                             ^~~~~~~~~~~~~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:96:12: error: type ‘<type error>’ argument given to ‘delete’, expected pointer
   96 |     delete visManager;
      |            ^~~~~~~~~~
/home/lucas/build/native/DAGMC-moab-5.1.0/src/src/geant4/app/exampleN01.cc:97:12: error: type ‘<type error>’ argument given to ‘delete’, expected pointer
   97 |     delete UI;
      |            ^~

[gonuke]

We are building against GEANT4 still, aren't we? (we're certainly burning a lot of CI cycles building it!) Is this still a problem @ljacobson64 @bam241 @makeclean ?

[ljacobson64]

Everything still works with Geant4 10.5 (which is what we use on the CI) and lower. Something in Geant4 changed with the 10.6 release that broke our ability to compile against it.

[helen-brooks]

I've just started a project commissioned by @makeclean with a student who needs to use Geant4 10.6+ because a downstream dependency requires a more recent version. So far I've identified the following from the Geant4 10.6 release notes which are of relevance:

• The preprocessor macros G4UI_USE and G4VIS_USE are deprecated in 10.6 - these are used in /src/geant4/app/exampleN01.cc to test whether to include some headers. This can be fixed easily via cmake checking the version from /path-to-geant4/lib/Geant4-X.Y.Z/Geant4ConfigVersion.cmake then adding some ifdef type statements.
• added namespace scope to MeshScoreMap - the class MeshScoreMap has been moved inside the class G4VScoringMesh. The file ExN01UserScoreWriter.cc needs the statement
  using MeshScoreMap = G4VScoringMesh::MeshScoreMap;

I'll tidy this up and make a PR.... (I also haven't checked the tests yet)