Executing a macro from my external hard drive

[dastudillo]

Your problem looks similar to this one:

Error merge root files using hadd

Hi all, I want to merge some root files under the folder(/data/yaokq/forward). I run the following code, but get errors.I’m obviously running in the “/data/yaokq/forward” folder, why does it show I don’t have permissions in the “/var/lib/snapd/void/” folder. uer:/data/yaokq/forward$ hadd output.root a.root b.root Error: hadd Target file:output.root hadd compression setting for all output:1 SysError in TFile::TFile: file /var/lib/snapd/void/output.root can not be opened Permission denied …

Which is not a ROOT problem, but apparently a general issue (feature?) with snaps, see for example

How to give snaps access to /somedir

How do I allow a snap package to access a particular folder with name "~/.directory"?

Since you are on Ubuntu, try instead using a precompiled version of ROOT (make sure it’s the one for Ubuntu 22.04!) instead of installing a snap package.