#9911's fixture_closure_rustc_discrimination passes on ANY rustc refusal from its red fixture's module, so its text-boundary claim is weaker than it reads

dag/gunbc/emitted_closure_compile_seed_growth.dag

@@ -144,12 +144,17 @@ import gunbc.seed_growth { SeedGrowthJustification }
 // the mandatory emitted-crate cargo check refuses it' -- a claim about a fixture the entry roster
 // cannot reach. This arm is where that claim EXECUTES instead of being asserted.
 //
-// ATTRIBUTION IS PART OF THE RED. The red fixture's closure is hundreds of modules and a bare
-// non-zero status could come from any of them, so the pair passes only when a diagnostic line
-// NAMES the fixture's own emitted module; otherwise the report reads 'unattributed' and the pair
-// FAILS rather than crediting a red the fixture did not cause. run_cargo's attribution symbol is
-// therefore a parameter of the caller rather than the injected mutation's constant: the required
-// phase attributes its own fault, the fixture route attributes the fixture.
+// ATTRIBUTION IS PART OF THE RED, AND IT IS TWO FACTS RATHER THAN ONE. The red fixture's closure
+// is hundreds of modules and a bare non-zero status could come from any of them, so the pair
+// requires a diagnostic line NAMING the fixture's own emitted module; otherwise the report reads
+// 'unattributed' and the pair FAILS rather than crediting a red the fixture did not cause.
+// run_cargo's attribution symbol is therefore a parameter of the caller rather than the injected
+// mutation's constant: the required phase attributes its own fault, the fixture route attributes
+// the fixture. THAT LOCATION SAYS WHERE AND NOT WHAT, so it is joined by the rustc ERROR CODE the
+// class renders as (E0308, mismatched types) read from the diagnostic header GOVERNING that
+// location -- without which the pair passed on any refusal reported in the right file, including
+// refusals that are not this class at all. The correction is recorded in full beside the roster
+// below.
 //
 // WHERE IT EXECUTES, STATED HONESTLY BECAUSE IT IS NOT THE MERGE PATH. The pair's ONE consumer is
 // `v1.compiler.compiler_tests_rust` `fixture_closure_rustc_discrimination`, emitted into
@@ -347,6 +352,50 @@ import gunbc.seed_growth { SeedGrowthJustification }
 // and cargo-actuation boundary; owning_dissolution_lane remains v1-hand-queue-drain, and the whole
 // selection surface deletes when those two effects are modeled and actuated.
 
+// HAND-RUST RECEIPT FOR THE RED ARM'S ERROR-CLASS CORRECTION (2026-09-02). Additions: EIGHT exact
+// declarations, enumerated rather than counted -- attributed_diagnostic,
+// cargo_verdict_probe_diagnostic, fixture_closure_attributed_diagnostic,
+// FIXTURE_RED_EXPECTED_RUSTC_CODE, and the four unit tests
+// the_attributed_diagnostic_is_the_header_governing_the_attributed_line and
+// an_unnamed_symbol_attributes_nothing_rather_than_the_first_diagnostic and
+// a_warning_naming_the_file_does_not_attribute_the_refusal and
+// a_red_of_the_wrong_error_class_does_not_pass_the_pair. Modified rather than
+// added: CargoVerdict (Completed gains probe_diagnostic), run_cargo (the scan moves into the pure
+// function), fixture_discrimination_passed, fixture_discrimination_report, and the unit test
+// a_green_baseline_does_not_pass_without_the_discrimination (one constructed variant). The roster
+// below therefore stands at 83 rows. WHY RUST IS STILL NEEDED, owning lane, deletion trigger and
+// current boundary are unchanged: the subject is still the cargo actuation boundary.
+//
+// WHAT THE CORRECTION IS, RECORDED BECAUSE IT IS A CLAIM THIS FILE PREVIOUSLY OVERSTATED. The pair
+// passed on ANY rustc refusal reported in the red fixture's own emitted module -- attribution was
+// a location, and a location says WHERE and never WHAT. A fixture edited into a syntax error, an
+// emitter regression producing an unresolved path, or an arity fault would each have reddened the
+// arm in the right file and been reported PASSED, while the text-boundary class the arm names had
+// stopped being its subject. The arm now additionally requires the rustc error code the class
+// renders as (`E0308`, cited from the rustc error index), attributed to the diagnostic GOVERNING
+// that location rather than to any header in the run. Nothing here changes where the arm executes
+// or what it may be cited as: it is still `#[ignore]`d candidate evidence, and the paragraphs
+// above about rungs stand unaltered. The one thing that now executes on every push is the PARSE
+// the red arm rests on, through the two unit tests above -- which is why the scan was factored out
+// of run_cargo rather than left inside a function that can only run by spawning a toolchain.
+//
+// THE CODE WAS MEASURED BEFORE IT WAS REQUIRED, not inferred from the class description. The
+// instrument is the arm's own enrolled invocation -- `cargo test --release -p v1-compiler --lib
+// fixture_closure_rustc_discrimination -- --ignored --nocapture` -- run on the pre-change tree,
+// where the red arm's diagnostic in the fixture's own emitted module is `E0308`. Re-derive it
+// there rather than trusting this sentence; a constant naming a code the fixture does not produce
+// would turn the arm permanently red, which is the failure mode this measurement rules out. THE
+// CODE AND NOT THE WORDING, and that is measured too rather than preferred: across the two runs
+// taken here the same E0308 arrived once as `mismatched types` and once as `arguments to this
+// function are incorrect`. A constant matching rustc's prose would have been red on the second
+// run without anything about the emitter changing; the error index code is the part of the
+// diagnostic rustc governs as an identity.
+// A SECOND NARROWING RIDES WITH THE FIRST, and it is about which diagnostics may attribute at
+// all: only an `error` does. An emitted module routinely collects warnings, they are printed
+// above the error that stopped the build, and a red attributed to one would name a line that
+// refused nothing -- so a file named only by warnings is unattributed rather than attributed to
+// an error elsewhere in the run that does not govern it.
+
 data emitted_closure_compile_seed_growth_justification: SeedGrowthJustification = SeedGrowthJustification {
   hand_authored_declarations: [
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "REQUIRED_EMIT_COMPILE_ENTRIES_DATA_NAME", field: WholeDeclaration },
@@ -359,6 +408,7 @@ data emitted_closure_compile_seed_growth_justification: SeedGrowthJustification
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "cargo_verdict_compiled", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "cargo_verdict_summary", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "cargo_verdict_probe_line", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "cargo_verdict_probe_diagnostic", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "cargo_verdict_stderr_tail", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "entry_own_subject", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "MutationSubject", field: WholeDeclaration },
@@ -380,18 +430,21 @@ data emitted_closure_compile_seed_growth_justification: SeedGrowthJustification
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "probe_crate_dir", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "write_probe_crate", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "run_cargo", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "attributed_diagnostic", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "write_probe_crate_files", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "FixtureClosureOutcome", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_closure_compiled", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_closure_reached_rustc", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_closure_attributed_line", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_closure_attributed_diagnostic", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_closure_summary", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_rust_module", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_closure_rustc_verdict", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_arm_diagnostic_lines", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "FixtureDiscrimination", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "FIXTURE_GREEN_PATH", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "FIXTURE_RED_PATH", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "FIXTURE_RED_EXPECTED_RUSTC_CODE", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_arm_verdict", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "run_fixture_closure_discrimination", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "fixture_discrimination_passed", field: WholeDeclaration },
@@ -427,6 +480,10 @@ data emitted_closure_compile_seed_growth_justification: SeedGrowthJustification
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "the_probe_root_does_not_exist_without_runner_temp", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "a_failed_restore_is_not_masked_by_a_non_terminal_fault_verdict", field: WholeDeclaration },
     DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "a_green_baseline_does_not_pass_without_the_discrimination", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "the_attributed_diagnostic_is_the_header_governing_the_attributed_line", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "an_unnamed_symbol_attributes_nothing_rather_than_the_first_diagnostic", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "a_warning_naming_the_file_does_not_attribute_the_refusal", field: WholeDeclaration },
+    DeclarationRef { module_path: "v1_compiler.emitted_closure_compile_host", decl_name: "a_red_of_the_wrong_error_class_does_not_pass_the_pair", field: WholeDeclaration },
   ],
   reason: "WHY RUST IS STILL NEEDED, and it is a REACHABILITY limit rather than a modeling gap. The subject is a required CI phase: it must run inside claim_executor, which is the only witness-executing consumer in the tree, and its stages are host effects -- writing an emitted tree to disk and spawning cargo over it. The required floor's hermetic envelope REFUSES host effects during preparation, so a .dag witness whose subject is a subprocess exit status is counted executed while its assertion never runs; DESIGN's Building-&-checks section records that boundary in as many words, and records that mocking the refusal would pass the witness against a fabricated exit status. So the phase has to live where the effects do, exactly as required_regen_host and partition_crate_boundary_host do.\n\nWHY IT IS ADMITTED AGAINST THE v1 FREEZE, ON PRECEDENT RATHER THAN ANALOGY. gunbc.v1_maintenance_standing v1_seed_standing admits a change by PURPOSE -- does it serve the v2 self-host program -- and the purpose test reaches the INSTRUMENT that measures that program, not only the program. This is that instrument in the most direct available sense: the self-host claim IS that the emitted tree compiles and behaves, and until now nothing on the merge path compiled an emitted tree at all. gunbc.floor_non_verdict_enrollment and gunbc.declaration_index_seed_growth are both admitted on that same footing. Classified against the five refused classes: NewLanguageBehavior -- no, the compile pipeline is byte-untouched, no diagnostic is added, moved or removed. NewCompatibilityObligation -- no, nothing is kept working for an old caller. NewEscapeHatchOrAdmissionRow -- no, and the direction is opposite: this adds a wall and adds no flag, env var or mode that skips it. SeedFeatureCompletion -- no, the seed compiler gains no capability; it compiles exactly what it compiled before. PublicSurfaceGrowth -- the nearest, and the test is a diff over THE EMITTED SEED'S EXPORTED DECLARATIONS: the file is wired by #[path] mod inside cli_run.rs exactly as declaration_index.rs, phase_profile.rs and partition_crate_boundary_host.rs are, so it contributes no pub mod line to the emitted lib.rs and its SeedRetainedIntrinsicRegistration carries has_pub_mod: false.\n\nWHAT IS NOT CLAIMED. This phase is not a compile of the corpus and must not be read as one: gunbc.whole_corpus_compile_admission refuses a whole-bundle compile on the default runner and records two EXIT=137 kills behind that refusal, so the subject is a bounded roster of entries in gunbc.ci_layer_roots required_emit_compile_entries. It carries no diagnostic count, no baseline and no ratchet -- a merge-blocking comparison against a population measured on the current tree is the tree-copied oracle DESIGN 5 rejects.",
   owning_dissolution_lane: "v1-hand-queue-drain" as RoadmapNodeId,

src/v1/compiler_tests_rust.dag

@@ -305,7 +305,11 @@ fn ct_fixture_closure_rustc_discrimination_test() -> String {
     "    /// THE PAIR IS THE SUBJECT, NOT EITHER ARM. The control must COMPILE, or a red below\n",
     "    /// proves only that something in the tree is broken. The red must be refused BY RUSTC and\n",
     "    /// ATTRIBUTED to the fixture's own emitted module, or a non-zero status from any of the\n",
-    "    /// hundreds of modules in its closure would pass for the fixture's own defect.\n",
+    "    /// hundreds of modules in its closure would pass for the fixture's own defect -- and the\n",
+    "    /// attributed diagnostic must be the ERROR CLASS this arm claims (rustc E0308, mismatched\n",
+    "    /// types), because a location says WHERE rustc refused and never WHAT. Without the code a\n",
+    "    /// fixture edited into a syntax error, or an emitter regression producing an unresolved\n",
+    "    /// path, reds in the right file and passes for the text-boundary subject it is not.\n",
     "    ///\n",
     "    /// #[ignore] AND WHY, STATED RATHER THAN LEFT TO BE DISCOVERED: this arm spawns cargo and\n",
     "    /// compiles two emitted crates, which is minutes rather than milliseconds, and\n",
@@ -328,10 +332,11 @@ fn ct_fixture_closure_rustc_discrimination_test() -> String {
     "        );\n",
     "        assert!(\n",
     "            crate::cli_run::fixture_discrimination_passed(&pair),\n",
-    "            \"the control must compile and the meaning-level red must be refused by rustc and attributed to its own emitted module; control={} red={} attribution={:?}\",\n",
+    "            \"the control must compile and the meaning-level red must be refused by rustc, attributed to its own emitted module, and carry the claimed error class; control={} red={} attribution={:?} diagnostic={:?}\",\n",
     "            crate::cli_run::fixture_closure_summary(&pair.green),\n",
     "            crate::cli_run::fixture_closure_summary(&pair.red),\n",
-    "            crate::cli_run::fixture_closure_attributed_line(&pair.red)\n",
+    "            crate::cli_run::fixture_closure_attributed_line(&pair.red),\n",
+    "            crate::cli_run::fixture_closure_attributed_diagnostic(&pair.red)\n",
     "        );\n",
     "    }\n\n")
 }

src/v1/stage0/src/cli_run.rs

@@ -40291,10 +40291,11 @@ pub use emitted_closure_compile_host::{
 /// public surface merely because Rust needs a path to it.
 #[cfg(test)]
 pub(crate) use emitted_closure_compile_host::{
-    fixture_arm_diagnostic_lines, fixture_closure_attributed_line, fixture_closure_reached_rustc,
-    fixture_closure_rustc_verdict, fixture_closure_summary, fixture_discrimination_passed,
-    fixture_discrimination_report, run_fixture_closure_discrimination,
-    run_function_value_adapter_discrimination, FixtureClosureOutcome,
+    fixture_arm_diagnostic_lines, fixture_closure_attributed_diagnostic,
+    fixture_closure_attributed_line, fixture_closure_reached_rustc, fixture_closure_rustc_verdict,
+    fixture_closure_summary, fixture_discrimination_passed, fixture_discrimination_report,
+    run_fixture_closure_discrimination, run_function_value_adapter_discrimination,
+    FixtureClosureOutcome,
 };
 
 /// The authority's own declared module path, for consumers outside this module.

src/v1/stage0/src/compiler_tests.rs

@@ -469,7 +469,11 @@ mod compiler_tests {
     /// THE PAIR IS THE SUBJECT, NOT EITHER ARM. The control must COMPILE, or a red below
     /// proves only that something in the tree is broken. The red must be refused BY RUSTC and
     /// ATTRIBUTED to the fixture's own emitted module, or a non-zero status from any of the
-    /// hundreds of modules in its closure would pass for the fixture's own defect.
+    /// hundreds of modules in its closure would pass for the fixture's own defect -- and the
+    /// attributed diagnostic must be the ERROR CLASS this arm claims (rustc E0308, mismatched
+    /// types), because a location says WHERE rustc refused and never WHAT. Without the code a
+    /// fixture edited into a syntax error, or an emitter regression producing an unresolved
+    /// path, reds in the right file and passes for the text-boundary subject it is not.
     ///
     /// #[ignore] AND WHY, STATED RATHER THAN LEFT TO BE DISCOVERED: this arm spawns cargo and
     /// compiles two emitted crates, which is minutes rather than milliseconds, and
@@ -492,10 +496,11 @@ mod compiler_tests {
         );
         assert!(
             crate::cli_run::fixture_discrimination_passed(&pair),
-            "the control must compile and the meaning-level red must be refused by rustc and attributed to its own emitted module; control={} red={} attribution={:?}",
+            "the control must compile and the meaning-level red must be refused by rustc, attributed to its own emitted module, and carry the claimed error class; control={} red={} attribution={:?} diagnostic={:?}",
             crate::cli_run::fixture_closure_summary(&pair.green),
             crate::cli_run::fixture_closure_summary(&pair.red),
-            crate::cli_run::fixture_closure_attributed_line(&pair.red)
+            crate::cli_run::fixture_closure_attributed_line(&pair.red),
+            crate::cli_run::fixture_closure_attributed_diagnostic(&pair.red)
         );
     }