MGS3039: a job nothing would grade

magus job fork, magus job apply and magus\job.put refused a job record that nothing would grade:

[MGS3039] job wave/docs writes and declares no check or goal: declare the check
  that proves the change, such as {"target": "test", "project": "."}

Nothing was written to the job store.

What fires it

• A record with write paths and neither a check nor a goal. Its worker could report done with no recorded run behind it.
• A record with no write paths that is not read_only. Empty write paths are correct only on a job that gathers evidence and writes nothing.

What to do

• For a job that writes, add the check that proves its change, or a goal.
• For a job that writes nothing, set "read_only": true.
• Otherwise, list the files the job edits as its write paths.

See also

• Leases: checks, goals and read-only jobs.