output-pipe
A deny rule by default: it refuses magus output piped into a filter, when magus projects the record itself, and names what to run instead.
What it catches
Magus output piped into a filter, when magus projects the record itself.
Why
magus projects its own record, so the filter is answering a question the command takes a flag for: -o name for ids, -o json for the whole record, -o template='{{.field}}' for one field, -s to silence progress. The half a reader cannot discover by trying again is the exit status: a pipe takes it from the LAST stage, so a failing magus reads as exit 0 and nothing says so. It denies on run, affected, x and every verb that is not a graph read. A read-only graph verb (refs, query, explain, describe) gets the same answer as the graph-pipe advisory, and a help request (--help, -h) passes: neither loses a failure.
Default and override
By default this rule takes the decision deny. A workspace sets it by name, in its root
magusfile, to deny, advise or off:
magus\guard.builtins({"output-pipe": "advise"})
A loosening takes effect once it is committed; a tightening applies at once.
Seeing it
A verdict names its rule in brackets, which is how you got here:
deny [output-pipe]: ...
A workspace that sets this rule to advise sees advise [output-pipe]: ... instead.
magus describe rule output-pipe prints the same entry at a terminal, and
magus describe rules lists every rule this workspace enforces.
See also
- All rules - what this workspace enforces, deny first
- The guard - how a verdict is reached and wired
- Setting a built-in rule - how a workspace changes this default