Archive a-declared-blocker-blocks

openspec/specs/agentic-harness/spec.md

@@ -2741,3 +2741,69 @@ check. It may legitimately not exist yet — that is what the wait is for.
 - **WHEN** a step names a change that does not exist in the workspace
 - **THEN** the run is not refused for that reason
 
+### Requirement: A chain does not start for a change its own declaration holds
+
+Where a change declares that it is blocked by another change, and that
+other change is still active, a chain for it SHALL be refused before its
+first stage.
+
+The refusal SHALL name the blocker. The remedy is not a setting: it is
+to land that change or to remove the declaration, and the message SHALL
+say which change is being waited for so either can be done.
+
+A blocker that has been archived SHALL NOT hold anything. That is what
+the declaration has always meant.
+
+A declaration naming a change that does not exist SHALL NOT hold
+anything either. That is a fault in the declaration, reported as one by
+the check that validates relations, and holding the run on it would hide
+the fault behind a refusal that reads as a schedule.
+
+#### Scenario: A blocker that has not landed
+
+- **WHEN** a chain is requested for a change declaring a blocker that is
+  still an active change
+- **THEN** the run is refused before the first stage, naming the blocker,
+  and no agent was invoked
+
+#### Scenario: A blocker that has landed
+
+- **WHEN** the declared blocker has been archived
+- **THEN** the run starts
+
+#### Scenario: A declaration naming nothing that exists
+
+- **WHEN** a change declares a blocker that is not a change of this
+  repository
+- **THEN** the run is not refused for that reason
+
+### Requirement: A declared blocker is not a validation failure
+
+A change that declares an unmet blocker SHALL remain valid.
+
+The declaration states a plan, and a plan not yet carried out is not a
+defect. Whether the repository validates and whether a run may start now
+are different questions, and only the second one is answered by the
+declaration.
+
+#### Scenario: Validating a repository holding a blocked change
+
+- **WHEN** the relations of a repository containing a change with an
+  unmet blocker are checked
+- **THEN** that change is not reported as invalid
+
+### Requirement: A blocked change cannot be started by asking differently
+
+There SHALL be no option that starts a chain for a change whose declared
+blocker has not landed.
+
+The declaration is a sentence its author wrote in a file under version
+control. An option to override it would move that decision out of the
+repository and into an invocation nobody reviews.
+
+#### Scenario: Asking again
+
+- **WHEN** a chain for a blocked change is requested in any way this
+  system offers
+- **THEN** it is refused
+