What were you trying to do that didn't work?

hwloc-gather-topology /tmp/topo
reports this 
 
 directory /sys/devices/virtual/dmi/id/
directory /sys/kernel/mm/hugepages/
grep: warning: stray \ before 0
directory /sys/fs/cgroup/
 
The problem is with this line in the savemntpnt function:  
 
if echo "$1" | grep "
012" ; then

If I understand it correctly, we want to check if there is a newline character.
I think we can achieve it with
 
if [[ $1 == $'\n' ]];
 
Test:
text="line1                                    
line2"
if [[ $text == $'\n' ]]; then echo "ignore"; fi
ignore

text="line1"
if [[ $text == $'\n' ]]; then echo "ignore"; fi
=> no match
I have reported the problem and proposed fix to hwloc-users@inria.fr upstream mailing list:

https://sympa.inria.fr/sympa/arc/hwloc-users/2025-08/msg00000.html

Tested with hwloc-2.11.1-3.el10.x86_64