nextflow run main.nf
Mark source directory as Generated Sources Root
in a terminal execute:
NXF_JVM_ARGS="-Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=5000,suspend=y" nextflow run main.nf --max=3
create a remote debug session (port 5000), put breakpoints at source/Madrid.groovy and attach to the remote session