publishDir directive not working with 'link' mode if the process is run inside a Docker (permissions)

[Rmulet]

I am not sure this is a real "issue", so I opened a discussion instead of reporting it as such.

Basically, it is as the title says: in processes that are run inside a Docker container, Nextflow fails to publish output files if the publishDir directive is set to "link". The underlying reason seems to be that the default umask on most Linux systems is 0022, which does not allow other users to modify that file. Since files generated via Docker are owned by a user that has a different UID as the host (as discussed in #1295), hard links cannot be created.

A workaround I've used is to modify the Docker container to create files with umask 0000, but I wonder if Nextflow could handle this transparently to the user.