Error when compiling macro: "'Pythia8/Analysis.h' file not found"

Newbie
1

Hi ROOTers,

I’m compiling a macro that uses Pythia8. It contains the line " #include “TPythia8.h” ", however this raises an issue when compiling the macro with the .L+ option:
/path/to/root/build/include/TPythia8.h:69:10: fatal error: ‘Pythia8/Pythia.h’ file not found

Pythia8 has been built with the shared library option, and ROOT was rebuilt with the Pythia8 binding:
–PYTHIA8_DATA=/path/to/pythia/pythia8240/share/Pythia8/xmldoc
–PYTHIA8_INCLUDE_DIR=/path/to/pythia/pythia8240/include
–PYTHIA8_LIBRARY=/path/to/pythia/pythia8240/lib/libpythia8.dylib

Additionally, my .bash_profile contains the following lines for Pythia8:
export PYTHIA8=/path/to/pythia/pythia8240
export PYTHIA8DATA=/path/to/pythia/pythia8240/share/Pythia8/xmldoc
DYLD_LIBRARY_PATH=${PYTHIA8}/lib:${DYLD_LIBRARY_PATH}

Indeed, PYTHIA8_INCLUDE_DIR contains the file Pythia8/Pythia.h. I’m also able to run this macro (with TPythia8 functioning) when just using the .L option. Might I be missing something obvious? Let me know if I can provide more information.
Thanks!

  • Jan
2

It appears that copying the contents of /path/to/pythia/pythia8240/include to /path/to/root/build/include solved this issue for the time being – I suppose this is how things should’ve been? If so, it’s a little unclear to me why this didn’t happen when building ROOT, given that I set the Pythia8 flags (in ccmake). And I suppose it’s a little less urgent, but I’m also a little confused by the fact that I was able to run things just fine as long as I excluded the “+” option from loading the macro. (i.e., ROOT did seem to know where Pythia8 was)

3

The issue persists with ROOT version 6.18 – the necessary Pythia include files were not copied during the ROOT build, and needed to be done manually. Here’s some more info I should have included before:
Operating System: macOS 10.14.5
CMake: version 3.14.5

4

Are you sure you built root with pythia8 option on?
What is output of command: root-config --features ?

5

Thank you for the reply!

I do believe I had the option set on (in ccmake), here is the output of root-config --features :

cxx11 asimage astiff builtin_afterimage builtin_clang builtin_davix builtin_freetype 
builtin_ftgl builtin_gl2ps builtin_glew builtin_llvm builtin_lz4 builtin_openssl builtin_tbb 
builtin_vdt builtin_xxhash clad cling cocoa davix exceptions explicitlink fftw3 gdml 
http imt libcxx opengl pch pythia8 python roofit shared sqlite ssl thread tmva tmva-cpu 
tmva-pymva vdt xml
6

I see, can you send please your macro so I can try to reproduce error?

7

Apologies for the delay! Here is a copy of the macro – I have included some configuration files for Pythia as well. The macro itself is at pythia_example/generation/generator.C, and can be run like:

root [0] .L generator.C+
root [1] Run()

Apologies that this isn’t quite a minimum working example. However, the issue previously seemed to come up simply from line 25: <#include “TPythia8.h”>
Ever since I manually copied the directories “Pythia8” and “Pythia8Plugins” from the Pythia installation to /path/to/root/build/dir/include/ , that hasn’t caused any issues, and things are working correctly. If those files should have been there in the first place, could this perhaps be a CMake issue?
Thanks for following up!

pythia_example.zip (38.1 KB)

8

Hi, I just wanted to follow up on this issue. I’m continuing to run into this issue, now with ROOT 6.20 (and Pythia 8244).

To recap, compiling a macro using TPythia8 raises this error:
/Users/jan/root/root-6.20.00/rbuild/include/TPythia8.h:69:10: fatal error: 'Pythia8/Pythia.h' file not found

(for exactness, I will report the paths exactly as they appear on my local machine, instead of using shorthand like path/to/root/build)

As I mentioned before, this problem is resolved if I copy some directories from Pythia’s include dir, containing .h files, into the ROOT build’s include dir:

cp -r /Users/jan/pythia/pythia8244/include/* /Users/jan/root/root-6.20.00/rbuild/include/.
After doing this, I can successfully compile & run ROOT macros using TPythia8.

However I assume this manual copy should not be necessary. I have built Pythia8 with the shared library, and built ROOT using the following flags in cmake, with the Pythia8 option turned on:

PYTHIA8_DATA = /Users/jan/pythia/pythia8244/share/Pythia8/xmldoc            
PYTHIA8_INCLUDE_DIR = /Users/jan/pythia/pythia8244/include                         
PYTHIA8_LIBRARY = /Users/jan/pythia/pythia8244/lib/libpythia8.dylib

I also have the following lines in my .bash_profile:

export PYTHIA8=/Users/jan/pythia/pythia8244
export PYTHIA8DATA=/Users/jan/pythia/pythia8244/share/Pythia8/xmldoc
DYLD_LIBRARY_PATH=${PYTHIA8}/lib:${DYLD_LIBRARY_PATH}

Without performing that manual copy I mentioned above, I can successfully run the ROOT tutorial pythia8.C and my own macros in interpreter mode, but compilation will fail with the error message at the top of this post.

As a side note, the ccmake description for PYTHIA8_INCLUDE_DIR is “Specify the directory containing Pythia.h.”. However while this should be given as /Users/jan/pythia/pythia8244/include (otherwise the build fails), the file Pythia.h is actually located at /Users/jan/pythia/pythia8244/include/Pythia8/Pythia.h.
This seems to be reflected in the include statement in TPythia8.h causing my error, which accounts for the Pythia8 subdirectory – the ccmake variable descriptions thus might be a little misleading.

Thanks again for the help!

Operating System: macOS 10.14.6
ROOT: 6.20/00
Clang: Apple clang version 11.0.0 (clang-1100.0.33.8)
CMake: version 3.17.0-rc1

9

@oshadura Could you take another look?

10

Hi!

Can you please print me PYTHIA8_INCLUDE_DIR from CMakeCache of your build?

Thanks a lot!

11

this one right?

1 Like
12

I will try to reproduce problem, locally, and let you know…

13

What is your command that you use to compile your macro? or you are using it from root interpreter?

14

I tried locally to build ROOT with PYTHIA8 and with this PR build was successful (minor changes) https://github.com/root-project/root/pull/5416

I used next variable while configuring ROOT:

 $ env | grep PYTHIA8
PYTHIA8=/home/oksana/CERN_sources/pythia8

Both cases using ROOT from build directory and from installation directory allowed me to execute root tutorials/pythia/pythia8.C without any error.

1 Like
15

@oshadura
Regarding your 1st comment: For example, I try to compile & run the Pythia8 tutorial code like the following:
root -x pythia8.C+
(This line works without the +, in which case I’m just using interpreter mode)

I will try the new PR in a little bit and let you know if I can get it running. Thanks!

16

I managed to run root -x pythia8.C+ as well…

17

@jaofferm I’d assume you have installed Pythia somewhere where your compiler does not look. You can add to the directories it checks by passing -I/wherever/you/installed/pythia8. For ROOT itself you can pass that as gSystem->AddIncludePath("-I/wherever/you/installed/pythia8")

1 Like
18

Hi Axel,
Thanks for the response! This solves my problem, now I can successfully compile my macro using TPythia8.

Out of curiosity, is this the expected functionality/solution? That is, since I gave the path to the Pythia8 shared library when building ROOT (via the -PYTHIA8_LIBRARY flag in cmake), I thought that it would have been automatically added to the include path for ROOT’s compiler.

19

Does it help if you do gSystem->Load("libEGPythia8") before running .x pythia8.C+? That might inject the required -I.

1 Like
20

Hi @Axel,
This also solves the problem! (sorry for the late reply)

I guess I didn’t quite understand how ROOT was handling these external libraries – this is a nice solution to my problem, since I can just put the gSystem->Load("libEGPythia8") command into a local rootlogon.C if I want to compile & run a ROOT macro with TPythia8 from the command line.

Thanks again to you and @oshadura for looking into this!

1 Like