Without this, we can have such errors:
RuntimeError: Unknown ldd line ldd: warning: you do not have execution permission for `/opt/slapgrid/shared/bzip2/449734bcc91bae01810a28d0af447a66/lib/libbz2.so' for /opt/slapgrid/shared/bzip2/449734bcc91bae01810a28d0af447a66/lib/libbz2.so.

Indeed, the permission for the lib itself is:
[root@fedora-riscv slapos]# ls -l /opt/slapgrid/shared/bzip2/449734bcc91bae01810a28d0af447a66/lib/libbz2.so.1.0.8
-r--r----- 1 slapsoft slapsoft 260080 May 10 10:32 /opt/slapgrid/shared/bzip2/449734bcc91bae01810a28d0af447a66/lib/libbz2.so.1.0.8

See merge request nexedi/slapos.core!632