uhm weird, I never saw this although I’m also on Arch and I use gdb on ROOT almost daily. I can’t reproduce the issue with 6.24 and master. Can you reproduce this in an Arch docker image maybe? If it’s an issue only with 6.22 or only on your particular system then I’m not sure there is much to do.
However you most likely want a version of ROOT compiled with debug symbols to run
gdb on it.