Documentation required for job definition with trigger field
It is not clear what fields are supported in job definition that contains a field "trigger". For instance, it would be very useful to be able to execute
before_script in such a job, but that is not supported.
The later would be useful in particular because, currently, there is no way to pass variables between jobs. The former workaround of passing artifacts between jobs (while extremely unreliable, still provided some value) is not possible with jobs with "trigger" field.