Issue 194: the host's own former archive stops every machine applying anything

Rule 5 of ADR 0163 (a former target is removed) met issue 162 (an archive has no removal) in the host's own archive, the first time a host carrying former targets replaced itself; every machine applied nothing from then on.
2026-10-02 02:42:19 +02:00
2 changed files with 64 additions and 62 deletions
@@ -0,0 +1,64 @@
+---
+status: located
+opened: 2026-10-02
+located-in: [mesh-host internal/apply (removeOrphan: a former target of a kind with no removal was fatal), mesh-host internal/store (Record keeps a former target for every kind, the host's own archive included)]
+fixed-by:
+amended-design:
+---
+
+# 194 — The host's own former archive stops every machine applying anything
+
+## What was observed
+
+2026-10-02, 00:34Z, on all four machines of this mesh, the first time a host carrying former
+targets ([ADR 0163](../../02-DECISIONS/0163-taking-a-module-over-is-a-comparison.md), rule 5,
+built in mesh-host 63) replaced itself with a newer host (mesh-host 64).
+
+The host delivers its own successor as an archive whose target is a versioned directory
+([ADR 0141](../../02-DECISIONS/0141-the-host-delivers-its-own-successor.md)): every new version
+is the same resource with a new target. Since mesh-host 63 the record keeps a resource's former
+target so the next apply removes what the host wrote under it
+([issue 097](../097-a-resource-that-changes-target-leaves-the-old-one-behind/00-report.md)). So
+the new host's first apply found the previous version's directory as a former target of its own
+archive, and asked the removal for an archive — which does not exist
+([issue 162](../162-an-archive-cannot-be-undeclared/00-report.md)):
+
+```
+applying "mesh-host.next@former:/usr/lib/nox-mesh-host/versions/3c906749ad27": no way to remove a "archive"
+0 resource(s) were applied and remain
+```
+
+Orphans are removed before any resource is applied on a converged machine, so the refusal ended
+every apply at its first step. Every machine reported `failed`, applied nothing, and would have
+gone on doing so: a host fix is itself an archive the same apply would have to write, and the apply
+never reached it. The machines kept running what they had; nothing new from the mesh could land.
+
+## Why it matters beyond this instance
+
+Two rules that are each right met in the one resource the host cannot afford to stop on. Rule 5
+says a former target is removed and said; issue 162 says an archive has no removal, deliberately,
+so an unassignment nothing can undo is never reported as done. Neither rule was wrong; their
+meeting was never tested, because the bed that would have found it is a host replacing itself
+under the new rule, and the first such replacement was the live one. The fix is narrow: a former
+target of a kind the host cannot remove is left in place, said, and forgotten — never fatal,
+because nobody dropped it. An archive the declaration dropped still refuses, as 162 has it.
+
+## What it took to recover
+
+The broken host cannot apply its own fix: the fix is delivered as an archive, and the apply fails
+before writing anything. On each machine the host's record (`/var/lib/mesh-host/state.json`) had to
+lose the one `@former:` entry by hand, once, so that the next push could write the fixed archive and
+stand aside for it. A manual edit of the host's record is otherwise never done; it is written here
+because the alternative was four machines that could apply nothing.
+
+## Open questions
+
+- Should `Record` keep a former target for a kind the host cannot remove at all? The trace is
+  useful; the removal it implies is not. Keeping it and letting the apply forget it is what the fix
+  does; not recording it would be quieter.
+- Should the host's own versions directory be cleaned by the launcher rather than by the apply —
+  the one archive whose former targets are genuinely removable, by the thing that knows which one
+  runs?
+- Is there a bed that replaces a host under the current rules before the live mesh does
+  (the proof row of [ADR 0141](../../02-DECISIONS/0141-the-host-delivers-its-own-successor.md) was
+  a single crossover, before former targets existed)?
@@ -1,62 +0,0 @@
---
-status: open
-opened: 2026-10-02
-located-in: []
-fixed-by:
-amended-design:
---
-
-# 195 — Every assigned module is counted as a bus user without a credential, and the real gaps are lost in the count
-
-## What was observed
-
-`status`, and `plan` for any machine, open with one line before anything else:
-
-```
-the bus's user list leaves out 49 user(s) the mesh has minted no credential for: <node>.<module>, …
-Each is a user that cannot connect until one is issued
-```
-
-The 49 are spread over four machines and name 26 distinct modules. Checked against the catalogue on
-2026-10-02:
-
-| what the module's definition says | modules |
-|---|---|
-| declares an own secret named `broker` | 1 — the route proxy, which needed a bus account for issue 191 |
-| declares no `broker` secret, and emits, consumes and serves nothing on the bus | 17 — the packet filter, the intrusion filter, the ssh daemon, the resolver configuration, the certificate authority, the broker itself and others |
-| declares no `broker` secret, and **emits events** | 1 |
-| not in this catalogue, so not checked | 7 |
-
-So the line counts every module assigned anywhere as a bus user. For almost all of them that is not a
-missing credential. A module with no `broker` secret has nowhere to receive one, and the mesh already
-says an account nothing reads is an orphan ([issue 078](../078-a-delivered-secret-is-accepted-under-any-name/00-report.md)).
-
-Two real gaps sit inside the count and cannot be told from the noise:
-
- **A declared `broker` secret was filled with a value that is not an account.** Before its account was
-  issued, the route proxy's plan on both machines already carried a sealed `broker` file, while the same
-  status line said no credential had been minted for it. A push had made the declared secret the way it
-  makes any own secret. The module would have started with a credential the bus does not know, and
-  nothing would have said why. It was found only because the account was being issued by hand.
- **A module that emits events declares no way to reach the bus.** Its events can go nowhere, and no
-  check refuses that.
-
-## Why it matters
-
-**A warning that is always on is read as never on.** The line names 49 users on every `status` and every
-`plan`. An operator, or an agent, learns to scroll past it. The one entry that was a real fault looked
-exactly like the 48 that were not.
-
-**The fault that was real is the silent kind.** A module whose broker credential is a generated value
-starts, fails to authenticate, and reports that three layers away from the cause. That is the failure
-the composition already refuses for a secret that was never made at all ("declared and not made"). Here
-a value was made, so the refusal never fired.
-
-## Open questions
-
- Should a bus user be composed for a module that declares no `broker` secret at all? If not, the line
-  shrinks to the modules that can actually use an account.
- Is a `broker` secret ever correctly made by the generic generator? If not, should composition refuse
-  a declared `broker` until it is issued, or should the mesh issue it as part of placing the module?
- Should a module that emits, consumes or serves on the bus be refused when it declares no `broker`
-  secret?