Check ROOT Installation


I am downloading HEP packages that are dependent on ROOT, and I keep getting ROOT-related errors (mainly with MadAnalysis5) and cannot seem to be able to solve them.
I want to check that I have ROOT correctly installed and all its paths are correctly configured; can you guide me on how to do so?

I downloaded ROOT via the Snap Store. and my system is Ubuntu 22.04.4 LTS and Python 3.10.12.

Best regards.

Welcome to the ROOT forum.

What kind of error messages do you get ?

To install ROOT you can follow the instruction on this page.


When (in MadGraph) trying to install MadAnalysis with “install MadAnalysis5” command, I get this error:

I couldn’t attach compilation_root.log file because this directory:
does not exist.

And in process of executing what’s written is blue (Default installation of Madanalys5 failed.
MG5aMC will now attempt to reinstall it with the options ‘–no_MA5_further_install --no_root_in_MA5’.
This will however limit MA5 applicability for hadron-level analysis.
If you would like to prevent MG5aMC to re-attempt MA5 installation, start MG5aMC with ‘./bin/mg5_aMC --debug’.) it produces these error:

And keeps repeating this to no end until I terminate it.

I raised this problem to MadAnalysis team on git (issues/248, I cannot seem to be able to paste the link) and they got to that I need to check my ROOT installation / install it properly.

Many thanks.i

Dear @Raghad ,

Thanks for reaching out to the forum! You can check you have a working ROOT installation in many ways, a good starting point would be

$: root
root [0] 


$: python
>>> import ROOT



The first method works, but the second produces this:

Is this normal?

Dear @Raghad ,

I re-read your initial post and I noticed you installed ROOT via the Snap store. For Python usage there is a slight difference as documented at Installing ROOT - ROOT (you just need to call pyroot at the command line).

In any case, it seems the initial step worked, can you try running some simple application with ROOT? For example you can choose any of our tutorials ROOT: Tutorials



  1. Given that I downloaded it from snap, is this why the packages keep giving me errors? Should I uninstall it and download it from another source?

  2. When executing the first two commands in the link you provided I get this:

#20 did not work and #21 poped-up this window:

The next two commands, produced this:

Many thanks.

Dear @Raghad ,

I believe the wording at the top of the page quite clearly says that those lines that you copy-pasted are just there as an example and do not represent a real tutorial.

#20 did not work and #21 poped-up this window:

I don’t know what #20 and #21 are

Please make sure that you are running a real program (whether C++ or Python) by browsing the many tutorials we have, downloading one of them, and running them with the proper command on your laptop.

Given that I downloaded it from snap, is this why the packages keep giving me errors?

Maybe yes or maybe no, it really depends on many factors, including how MadGraph looks for the ROOT libraries at configuration time and whether you are telling the MadGraph build system where to find them.

Should I uninstall it and download it from another source?

Not necessarily, if you install from another source you will get the same software, maybe it will make things easier for you though depending on what you choose to do. I could imagine that if you take the time to build a ROOT installation from sources then at that point you will have all the necessary ingredients to properly build MadGraph as well (it’s like doing N and N+1 in that sense). But again, it should not be necessary.


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