Issues with RDMA an unsquash

[fnikolai]

When singularity --unsquash is enabled, the RDMA fails.

Logs:

(gdb) backtrace
#0  0x00007fffe48e33f5 in try_all_drivers () from /usr/lib64/libibverbs.so.1
#1  0x00007fffe48e3bef in ibverbs_get_device_list () from /usr/lib64/libibverbs.so.1
#2  0x00007fffe48e12ba in ibv_get_device_list () from /usr/lib64/libibverbs.so.1
#3  0x00007fffdfdd933e in btl_openib_component_init () from /opt/cluster/openmpi/4.1.2/gcc/11.2.0/lib/openmpi/mca_btl_openib.so
#4  0x00007ffff49003f2 in mca_btl_base_select () from /opt/cluster/openmpi/4.1.2/gcc/11.2.0/lib/libopen-pal.so.40
#5  0x00007fffe5e16454 in mca_bml_r2_component_init () from /opt/cluster/openmpi/4.1.2/gcc/11.2.0/lib/openmpi/mca_bml_r2.so
#6  0x00007ffff632f6d4 in mca_bml_base_init () from /opt/cluster//openmpi/4.1.2/gcc/11.2.0/lib/libmpi.so.40
#7  0x00007ffff637ca74 in ompi_mpi_init () from /opt/cluster//openmpi/4.1.2/gcc/11.2.0/lib/libmpi.so.40
#8  0x00007ffff6313b5e in PMPI_Init () from /opt/cluster//openmpi/4.1.2/gcc/11.2.0/lib/libmpi.so.40
#9  0x000000000040348a in main ()