011: measured, and the premise was wrong — the graph is not missing

The effort was opened to ask whether the catalogue's missing structure is a
graph. It is not missing. 126 manifests, 103 edges, no cycles, nothing dangling,
deepest chain of five — and a resolver in the SDK that topologically sorts them,
already called by the tool loader at startup, the installer when syncing modules
onto a node, and the delivery coordinator when expanding what a change affects.

It already does something this effort assumed would need designing: a
requirement on another module's provision is treated as an implicit edge to the
module that provides it. So "ordering by the graph", which ADR 0043 makes the
control plane's job, is a thing to call rather than a thing to build.

The one place the graph is wrong, it is wrong about the substrate. A module
needing a database declares `provider: postgres` inside `provisions:` — which is
what a module OFFERS — so the resolver, which reads `dependencies:` and
`requires:`, never sees it. Three edges are invisible this way, and they are the
mesh's own database, the mesh's own broker, and the work engine's database.

The consequence is measurable: computing what a working mesh needs from the
declared graph gives registry -> sdk -> mesh -> meshware. Four modules, four
levels, no database. Arithmetically correct and obviously wrong, for exactly one
reason — a field that means "depends on" is not read as one. That is
04-ISSUES/003 in a new form: not a key nothing reads, but a key read as
something other than what it means.

Two latent defects, both contrary to ADR 0008 and both in the component ADR 0043
makes responsible for ordering a host will apply without question: a cycle warns
and falls back to input order, and a dependency that does not exist warns and
continues. Neither has fired, because the catalogue currently has no cycles and
nothing dangling, which is why nobody has noticed.

And placement is decided in the catalogue: a provision pins itself to a named
node in the manifest. Which node runs what is an inventory decision — tier 2 by
the skeleton's own test — so a second node cannot provide the mesh's database
without editing the module that consumes it.

What the graph would DELETE is currently nothing. What it would add is three
declarations that no manifest uses today: excludes, a required node capability,
and an interface with adapters. Whether they would be used is not measured, and
zero usage is equally consistent with nobody needing them and nobody being able
to express them.
This commit is contained in:
2026-08-26 22:35:39 +02:00
parent 278f7427ed
commit c3a2984b3e
2 changed files with 153 additions and 1 deletions
@@ -17,6 +17,17 @@ touches:
Whether the catalogue's missing structure is a **graph** — modules declaring what they need,
what they offer, and what they exclude — and what that replaces.
**Measured, and the premise was wrong: the graph is not missing.**
[`analysis.md`](analysis.md) — 126 manifests, 103 edges, no cycles, nothing dangling, and a
resolver that topologically sorts them, already called by the tool loader, the installer and
the delivery coordinator. What the effort assumed would need building is a thing to call.
What survives is narrower: three declarations that do not exist (`excludes`, a required node
capability, an interface with adapters), and two defects worth fixing whatever else is
concluded — `provider:` is a dependency edge that is not read as one, which makes the closure
for a working mesh come out without a database; and the resolver continues past a cycle and
past a missing dependency, contrary to ADR 0008.
[ADR 0017](../../02-DECISIONS/0017-modules-outside-the-core-are-grouped-by-domain.md) proposes
grouping modules by domain. [Research 005](../005-domain-grouping/analysis.md) measured that
proposal and found its evidence holds in exactly one place — reachability — which
@@ -108,7 +119,10 @@ integration being wrong looks like from the outside.
| Question | Why it is open |
|---|---|
| What does the graph **delete**? | If modules gain declarations and lose nothing, this is motion rather than progress. The effort has not finished until it names what stops existing. |
| ~~What does the graph **delete**?~~ | **Answered, and not as expected** — nothing, because it already exists. The honest list of what a graph would remove is currently empty, and what it would *add* is three declarations. [`analysis.md`](analysis.md). |
| Would the missing declarations be used? | Zero manifests declare exclusions or capabilities, which is equally consistent with *nobody needs them* and *nobody can express them*. Nothing measured separates those. |
| Should `provider:` become a real edge, or should the relationship be declared twice? | It names a module and means *depends on*. Reading it as an edge fixes the closure; the alternative is requiring the consumer to also list it under `dependencies:`, which is duplication a resolver already avoids elsewhere. |
| Should placement leave the catalogue? | A provision pins itself to a named node, in the manifest. Which node runs what is an inventory decision — tier 2 by the skeleton's own test — and having it in tier 4 means a second node cannot provide the mesh's database without editing the module that consumes it. |
| Where does resolution happen — mesh or platform package manager? | The mesh must model mesh-level edges. Whether it also resolves operating-system packages, or delegates, decides whether a solver has to be written. |
| Is an interface a module, or a name? | Arch makes it a name that packages claim. Making it a module gives it a manifest, an owner and a place to document the contract — and a thing with no implementation to install. |
| What does an exclusion mean for something already installed? | Refuse the install, or make the conflict visible and let it be decided. The second is a policy surface; the first is a package manager. |