Valgrind dies at assertion '!overlap' failed

[Wile_E_Coyote]

The same problem is shown in (Scientific Linux 7.7, gcc 4.8.5, your root_v6.20.04.Linux-centos7-x86_64-gcc4.8.tar.gz binary release):

Crash without errors warning (Stack)

Here is the output from valgrind for a loop over small number of files filename.txt (19.5 KB) And here for more files which makes root crash filename2.txt (19.5 KB)