Top level symlinks cannot be replicated inside the container

[Nortamo]

Singularity always follows symlinks provided as arguments to bind mounts, so there is currently no known way
to replicate e.g /appl -> /pfs/lustrep3/appl inside the container mount namespace.

This leads to issues when doing nested calls to the wrappers.

Quick fix is to call the _bin folder which will contain symlinks if the bin <-> _bin bind mount has not been applied. or then alternatively using the --writable-tmpfs and create a symlink at container startup.