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MGS1038: a magus.project option was removed

A magusfile sets a key that magus.project used to accept:

[error] [MGS1038] magus.project: targets["build"]: option "exclusive" was removed in
v0.5.0 with no replacement; slots and memory_mb are the only concurrency dials, so delete
the key

Why this stops the load instead of ignoring the key

An option magus does not recognize is usually ignored with a warning, because it may come from a NEWER magus: rejecting it would stop the workspace loading, including the command that builds a binary new enough to read it.

A removed option is the opposite case. It came from an OLDER magus, and you are already on the newer one. The ignore path would tell you to upgrade, which sends you in a circle, and meanwhile the value you declared does nothing. Stopping with the key's name and what to do is the only answer that ends the loop.

What to do

Follow the message. Each removed option names its replacement, or says it has none.

option removed in instead
exclusive v0.5.0 nothing: delete the key

exclusive

It asked for a target, or every target in a project, to run with no other target beside it. It was meant for a target that uses the whole machine, and measured across every declaration it never did: most protected nothing, and where the engine honored it, it serialized every other gate member behind one target until the stall watchdog took the run.

slots and memory_mb are the concurrency dials a target has. A target that must not run beside a peer is making a claim about a shared resource, such as a tag namespace or a branch it pushes, and the place to express that is its own CI job rather than a policy on the target. ADR 0001 records the reasoning and the measurement.

Magusfile diagnosticsLanding page for MGS1xxx diagnostics that flag authoring mistakes in a workspace's magusfile, such as missing targets or unresolved declarations. SpellsA spell is a library of tool-native ops (go-build, cargo-clippy, eslint) plus cache metadata that your magusfile composes into runnable targets. ChangelogEvery change to magus, newest first, in Keep a Changelog format, starting with the unreleased entries. Generated from changes/unreleased/ and releases/*.yaml. ADR 0005: deterministic answersThe v0.5.0 finishing pass, recorded in full. A stalled multi-agent change showed where agents improvise and where magus stays silent. The person drives; magus answers from the graph, the job store and typed APIs, and prints what to run. Every idea and use case raised during the pass is listed here with its state, so this page is also the plan.
MGS1038magusfileoptionsupgraderemovedexclusive
Last updated (79e6c198)
Glossary

Workspace

The magus root directory that owns a set of projects and shared config; the unit magus operates over. Workspace in full.

Project

A directory magus recognizes as a unit of work (it has a magusfile); the unit of caching, scheduling, and dependency tracking. Project in full.

Magusfile

The magusfile.buzz that declares a project's targets (as export funs) and binds its spells. Magusfile in full.

Target

A named operation (build, test, ...) you invoke with magus run <target>; it may compose a spell's tool-native operations and depend on other targets. Target in full.

Op

A single tool-native command a target composes (long form: operation); the middle of the work hierarchy (Spell to Op to Target). Op in full.

Engine

The interpreter a magusfile runs on; magus embeds the Buzz engine. Engine in full.

CI

An ordinary target you compose yourself with ctx.needs; magus does not hardcode its stages. It is the anchor magus affected ci keys off, and ci strips the rw charm. CI in full.

Slot

One unit of the pool's capacity. A target acquires the slots it needs to run (most take one) and releases them when it finishes; the pool tracks capacity (total slots), running (acquired), and queued (blocked). Slot in full.

Concurrency

How many targets run at once. It is bounded by the pool's capacity and set with --concurrency, MAGUS_CONCURRENCY, or the concurrency config key. Concurrency in full.

Invocation

One magus process's recorded facts (the targets it finished, their outcomes, the lease it acted as, and the session it ran in when a host delivered one), kept in a repo-scoped store every worktree shares. magus session lists them; the store prunes itself by last-fact age. Invocation in full.

Job

The unit of delegated work, and one row of the job store: what an orchestrating agent handed out, with its goal, the checkpoint it was cut against, the paths it may write or must not touch, and the one check it runs. A job's holder is either a session, for work an orchestrator handed out, or the daemon, for its own maintenance. The store records; the agent guard is what reads those facts back when grading a write. Job in full.

Run

One target executing under one magus invocation, such as magus run test web or magus affected ci. A run keeps its captured output behind an output reference. Every magus run is a run whether or not any job asked for it; see Job for how the two relate. Run in full.

Conventions

This page uses none of the site's convention markers. The full set is on the conventions page.