Can't use tools smoothly or properly on Root- 6.20

Hi, I’m trying to open ROOT file, plot a 2D spectra, perform a simple cut using root 6.20. Suddenly every operation on root has been slowed down and can’t use any tools properly.
How to fix the problem?

ROOT Version: 6.20
Platform: Ubuntu
Compiler: C++

what do you mean with “slowed down” exactly? Is 6.20 responding more slowly to clicks than 6.18?
How did you install each of the versions?


Sorry for the mistake, previously given version is not correct.
I’m using ROOT with specification given below.
ROOT Version: 6.19/01
Built for linuxx8664gcc on Jun 10 2019, 11:07:18
From heads/master@v6-19-01-158-gf6b009d39b
I have installed ROOT by directly cloning from git.
My system is Ubuntu-18.04.4 LTS

This version became slower only for some of the ROOT files irrespective of their size. GUI isn’t responding properly, I’m unable to perform any kind of operation for those particular files.

Uhm that’s weird, what do you mean with “GUI isn’t responding properly” exactly? Button clicks do not have any effect? If the problem is with rootbrowse, this might be

Otherwise can you try a more recent ROOT version? Installation instructions are at .

If you see that the GUI is definitely slower in 6.20 or 6.22 (6.19 is a development release, not a stable release), please provide step-by-step instructions for us to reproduce the problem, including any necessary input files.


Okay, an error occurred while trying to build the version 6.22 from source file. Please help me out to fix the error.

The build completed successfully.

Then I guess you used make install or a similar command, and by default ROOT tries to install in/usr/local, but as a normal user you don’t have permissions.

I suggest you configure a different install location, e.g. ~/root-v622, with cmake -DCMAKE_INSTALL_PREFIX=/home/sahana/root-v622 && mkdir ~/root-v622 && make -j4 install.

Note however that compiling ROOT from source is the most advanced of the ways you can install ROOT, there are several simpler alternatives.


This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.