> ok, thank you for your information. I cannot reproduce this problem, I use vanilla Ubuntu 
> LTS 22, ROOT binary kit root_v6.30.02.Linux-ubuntu22.04-x86_64-gcc11.4 from root.cern.ch 
> and latest midas from git.
> 
> something is wrong with your ubuntu or with your c++ standard library or with your ROOT.
> 
> a) can you try with root_v6.30.02.Linux-ubuntu22.04-x86_64-gcc11.4 from root.cern.ch
> b) for the midas build, please run "make cclean; make cmake -k" and email me (or post 
> here) the complete output.

also, please email me the output of these commands on your machine:

daq00:midas$ ls -l /lib/x86_64-linux-gnu/libstdc++*
lrwxrwxrwx 1 root root      19 May 13  2023 /lib/x86_64-linux-gnu/libstdc++.so.6 -> libstdc++.so.6.0.30
-rw-r--r-- 1 root root 2260296 May 13  2023 /lib/x86_64-linux-gnu/libstdc++.so.6.0.30
daq00:midas$ 

and

daq00:midas$ ldd $ROOTSYS/bin/rootreadspeed 
	linux-vdso.so.1 (0x00007ffe6c399000)
	libTree.so => /daq/cern_root/root_v6.30.02.Linux-ubuntu22.04-x86_64-gcc11.4/lib/libTree.so (0x00007f67e53b5000)
	libRIO.so => /daq/cern_root/root_v6.30.02.Linux-ubuntu22.04-x86_64-gcc11.4/lib/libRIO.so (0x00007f67e4fb9000)
	libCore.so => /daq/cern_root/root_v6.30.02.Linux-ubuntu22.04-x86_64-gcc11.4/lib/libCore.so (0x00007f67e4b08000)
	libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f67e48bd000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f67e489b000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f67e4672000)
	libNet.so => /daq/cern_root/root_v6.30.02.Linux-ubuntu22.04-x86_64-gcc11.4/lib/libNet.so (0x00007f67e458b000)
	libThread.so => /daq/cern_root/root_v6.30.02.Linux-ubuntu22.04-x86_64-gcc11.4/lib/libThread.so (0x00007f67e4533000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f67e444c000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f67e5599000)
	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f67e43d6000)
	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f67e43b8000)
	liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f67e438d000)
	libxxhash.so.0 => /lib/x86_64-linux-gnu/libxxhash.so.0 (0x00007f67e4378000)
	liblz4.so.1 => /lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f67e4358000)
	libzstd.so.1 => /lib/x86_64-linux-gnu/libzstd.so.1 (0x00007f67e4289000)
	libssl.so.3 => /lib/x86_64-linux-gnu/libssl.so.3 (0x00007f67e41e3000)
	libcrypto.so.3 => /lib/x86_64-linux-gnu/libcrypto.so.3 (0x00007f67e3d9f000)
daq00:midas$ 

K.O.