[BUG] spython recipe COPY --chown from Dockerfile is not supported

[ReHoss]

Using spython recipe to transform a Dockerfile, the following instruction is wrongly translated
COPY --chown=user:group

[vsoch]

We definitely don't have support for that. How would a custom user make sense in a Singularity container? You'll always be running as your user.

[ReHoss]

Indeed, I am not sure yet if it does make sense to do that, I have to dive into Singularity again.
However, right now the option --chown=user:goup is not recognised as is by spython recipe but is silently considered as a directory. A warning or an error should be triggered.

Best,

[vsoch]

If you’d like to contribute a PR to address this (likely just searching for it and filtering it out) it would be appreciated.