log.error and error does not print to sderr

[maxulysse]

New feature

I would love an easy way to print to stderr.
log.error print to stdout, but prints in red with the ERROR keyword before.
I understand that it's for logging purpose first, but I would love for an easy way print to stderr in Nextflow .
While we're at it, if we could use the same method to print similar messages in the plugins that would be perfection.
If I look at this for example: https://github.com/nextflow-io/nf-schema/blob/ecf159f53d45200ef70920c03e75077b5689a386/plugins/nf-schema/src/main/nextflow/validation/ValidationExtension.groovy#L319-L323
the log.error is printed to stdout while the other message is indeed printed to both stdout and stderr.

Use case

I would want to be able to print my error message from the pipeline side, error and exit right away without catching other unrelated errors.

Suggested implementation

I think the error method should the right way to do it, if it was printing to stderr.
Still I did notice some unrelated messages that appears and throws some red herrings that confuses users (and me too)