[legacy][nov20] Errors installing Geant4

[fuhlig1]

There are two problems with the Geant4 installation at least on macosx 10.15 but probably also for other versions.

1. OpenGL isn't found if xquartz is not available. I encountered the problem after I uninstalled the brew xquartz package and use the new libx11 and mesa-glu packages from brew. The problem is that /usr/local isn't in the search path for GL on macosx. This can be fixed with the following patch.

--- a/cmake/Modules/FindXQuartzGL.cmake 2020-05-29 14:46:48.000000000 +0200
+++ b/cmake/Modules/FindXQuartzGL.cmake 2021-01-13 11:14:19.000000000 +0100
@@ -49,17 +49,17 @@
 set(CMAKE_FIND_FRAMEWORK NEVER)
 
 find_path(XQuartzGL_INCLUDE_DIR GL/gl.h
-  PATHS /usr/X11R6/include /opt/X11/include
+  PATHS /usr/X11R6/include /opt/X11/include /usr/local/include
   NO_DEFAULT_PATH
   )
 
 find_library(XQuartzGL_gl_LIBRARY GL
-  PATHS /usr/X11R6/lib /opt/X11/lib
+  PATHS /usr/X11R6/lib /opt/X11/lib /usr/local/lib
   NO_DEFAULT_PATH
   )
 
 find_library(XQuartzGL_glu_LIBRARY GLU
-  PATHS /usr/X11R6/lib /opt/X11/lib
+  PATHS /usr/X11R6/lib /opt/X11/lib /usr/local/lib
   NO_DEFAULT_PATH
   )

2. I had to switch of the GEANT4_USE_PYTHON option when compiling Geant4. Enabling of this option depends on boost_python which is not build with FairSoft legacy. I never saw the problem before since I had boost_python in /usr/local which was found automatically but which I removed recently. To solve the issue I would propose to install boost_python when building boost. I am not sure why this isn't done since with FairSoft legacy jun19 it is installed.

[dennisklein]

• Can you pls provide the boost build logs (configure, build, install) to get to the bottom why boost_python is not built for you?
• Have you installed the system prerequisites listed in legacy/setup_macos.sh (minus xquartz which you have commented on)?

[fuhlig1]

The problem is that the autodetection of boost does not find the python installion from brew properly. The issue is described in their recipe. By the way the have a separate recipe for boost-python.

https://github.com/Homebrew/homebrew-core/blob/d1c9b3c3bba5c83a16f146a29dcef3120c0f4a29/Formula/boost-python3.rb#L48

If I pass the proper information to b2 at the configuration stage libboost_python is build. My command is

./bootstrap.sh --prefix=/opt/fairsoft/nov20 --with-python=python3 --with-python-root=/usr/local/opt/python@3.9

After the successful installation of libboost_python also the compilation of Geant4 work without problems

[dennisklein]

I am preparing a patch release for nov20 also covering the other reported issues from last week, regarding:

• boost_python: I will include this fix for the python arguments
• opengl: We will track the development in homebrew package: Replace depends_on :x11 #369, but for now I tend to stick with xquartz. We can switch to brew's mesa-gl in the next FairSoft release. Unless we find a very good reason why we need to support it for the nov20 release. What do you think?

[fuhlig1]

For the OpenGL issue I opened a pull request upstream (Geant4/geant4#17)

[fuhlig1]

• boost_python: How do you want to fix it? Do you want to use FindPython before and use the found information as input for the boost installation?
• openGL: Would it hurt to add the patch? In case xquartz is installed it will not make a difference, in case xquartz isn't installed but libx11 and mesa-glu the Geant4 configuration would not fail.

[dennisklein]

boost_python: How do you want to fix it? Do you want to use FindPython before and use the found information as input for the boost installation?

See

FairSoft/FairSoftConfig.cmake

Lines 59 to 63 in 7e1412f

	if(APPLE)
	execute_process(COMMAND brew --prefix python OUTPUT_VARIABLE python_prefix)
	string(STRIP "${python_prefix}" python_prefix)
	set(PYTHON_EXECUTABLE "${python_prefix}/bin/python3" CACHE FILEPATH "Python executable" FORCE)
	endif()

. I would pass the python root dir like this and wired it up properly in the boost configuration.

openGL: Would it hurt to add the patch? In case xquartz is installed it will not make a difference, in case xquartz isn't installed but libx11 and mesa-glu the Geant4 configuration would not fail.

Ok, I will add the patch. But let it be noted, that it is a very dirty hack in the current form:

• The patched CMake file is called FindXQuartzGL.cmake and now it will find brew mesa...
• The hard-coded prefix might be wrong, it should rather be generated from brew --prefix.

[fuhlig1]

Ok, I will add the patch. But let it be noted, that it is a very dirty hack in the current form:

- The patched CMake file is called FindXQuartzGL.cmake and now it will find brew mesa...

I think the name is not very well chosen. If I understand the code correctly they want to avoid that GL from the system is used.

- The hard-coded prefix might be wrong, it should rather be generated from brew --prefix.

That's much better.

Better don't add the patch. n the moment I am the only person with such an installation and I know what I have to do manually. If we keep xquartz in the setup description for mac the probability that anyone else has such an installation is low.

[dennisklein]

The fixes are included in the nov20_patches branch:

• 13c85f3
• 0a99a74
  and will be included in the next patch release.