ww: print final status for explicit test failures

docs/build-system.md

@@ -7190,6 +7190,159 @@ must match exactly. Existing package execution, timeout, interruption,
 transaction, persistence, byte-identity, and cleanup owners continue to prove
 the mechanisms this slice does not alter.
 
+### 11.34 Implemented final `FAIL` for explicit ordinary test failures
+
+An ordinary `ww test` request with an explicit target now ends its ordered
+standard output with exactly one command-owned `FAIL\n` when test setup, build,
+or execution fails. The line follows every package result, including successful
+packages ordered after an earlier failure. It applies to one or many explicit
+directory, recursive, dotted-directory, or raw-file targets; filters and list
+mode; and the private execution of a retained test. It does not apply to bare
+implicit-current-directory `ww test`, `-c`, `-S`, `ww build`, command-line
+usage/shape or output preflight rejection, publication-only failure,
+capture-only failure, cleanup-only failure, allocation/systemic coordinator
+failure, or later direct execution of a retained binary.
+
+#### Pinned Go evidence and classification
+
+The sole authority is official Go 1.26.5 at commit
+`c19862e5f8415b4f24b189d065ed739517c548ba`:
+
+- `runTest` reports setup errors, writes the per-package setup-failure result,
+  and sets the command exit status
+  ([`cmd/go/internal/test/test.go`, lines 1010–1061](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/test.go#L1010-L1061)).
+  It then creates a root `go test` action owned by `printExitStatus`, orders all
+  package print actions, and executes that root
+  ([lines 1099–1124](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/test.go#L1099-L1124)).
+- `builderTest` constructs the ordinary build/run/clean/print chain and gives
+  the run and print boundaries the failure handling needed to reach ordered
+  output; its compile-only branch instead uses a dependency-sensitive nop
+  print action
+  ([lines 1133–1169 and 1185–1366](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/test.go#L1133-L1366)).
+- `(*runTestActor).Act` turns a dependency build failure into a package test
+  result and sets exit status 1
+  ([lines 1436–1521](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/test.go#L1436-L1521)).
+  Every non-nil execution error, including nonzero exit or abnormal/start
+  failure, likewise sets the exit status and emits the package failure result
+  ([lines 1644–1774](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/test.go#L1644-L1774)).
+- `builderCleanTest` and `builderPrintTest` put cleanup and captured package
+  output before the root status action
+  ([lines 2237–2259](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/test.go#L2237-L2259)).
+  `printExitStatus` then prints exactly `FAIL\n` when at least one package
+  argument was explicit and the global exit status is nonzero
+  ([lines 2262–2284](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/test.go#L2262-L2284)).
+- Official `test_status.txt` requires a failing package, a later successful
+  package, and a final standalone `FAIL\n`
+  ([lines 3–6](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/testdata/script/test_status.txt#L3-L6)).
+  Official `test_syntax_error_says_fail.txt` requires `FAIL` for an explicit
+  test build/setup syntax failure
+  ([lines 1–13](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/testdata/script/test_syntax_error_says_fail.txt#L1-L13)).
+- `testFlags` records explicit file operands in `pkgArgs`
+  ([`cmd/go/internal/test/testflag.go`, lines 219–290](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/test/testflag.go#L219-L290));
+  `PackagesAndErrors` turns those files into the command-line package
+  ([`cmd/go/internal/load/pkg.go`, lines 2895–2918](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/load/pkg.go#L2895-L2918)),
+  which `GoFilesPackage` constructs
+  ([lines 3244–3315](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/load/pkg.go#L3244-L3315)).
+
+Those source rules and official assertions are behavior directly implemented
+or asserted by pinned Go. The single-explicit-package and raw-file cases are
+derived from `len(pkgArgs) != 0` and the explicit-file loading path. The bare
+implicit exclusion is derived from empty `pkgArgs`. The compile-only and
+publication-only exclusions are derived from their uncleared dependency
+failure preventing the root actor under the pinned work executor
+([`cmd/go/internal/work/exec.go`, lines 134–205](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/go/internal/work/exec.go#L134-L205)).
+
+#### Fresh four-axis audit and direct pre-fix measurements
+
+The bounded audit considered all four permanent axes and selected only this
+test-command status gap:
+
+- **Go-like build:** pinned unresolved-symbol handling and its undeclared-main
+  case are owned by `(*ErrorReporter).errorUnresolved`
+  ([`cmd/link/internal/ld/errors.go`, lines 29–65](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/link/internal/ld/errors.go#L29-L65)),
+  with official assertions in `TestUndefinedRelocErrors`
+  ([`cmd/link/internal/ld/ld_test.go`, lines 19–45](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/link/internal/ld/ld_test.go#L19-L45))
+  and `issue10978/main.go`
+  ([lines 5–27](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/link/internal/ld/testdata/issue10978/main.go#L5-L27)).
+  Direct Cstage and WWstage no-main builds both exited 1 with identical linker
+  diagnostics and no output. This candidate was aligned.
+- **Go-like test:** an explicit failing directory made both stages exit 1 with
+  empty stderr and byte-identical 207-byte stdout (SHA-256
+  `3d0d44d5d9c4d4d95446382807ee092a611f19b43dc3013cf8df76f135cb5c46`),
+  ending at its package failure rather than a standalone marker. A failing then
+  successful `-j 2` request had byte-identical 384-byte stdout (SHA-256
+  `4623567924df78375fcca84ff797b7cb89d06d3fd5382704d8b9ebb79916b9d9`)
+  ending at the successful `ok` result. A raw-file failure had byte-identical
+  121-byte stdout (SHA-256
+  `8db356ffc5b3a6d9df3308bfba8301329c5c07ce30c5ccd5cc5ee22a6c43331c`)
+  ending at harness accounting. Explicit missing-import build failure likewise
+  lacked the final marker. These directly measured pre-fix WW facts establish
+  the selected external difference. Bare implicit and `-c` failures already
+  omitted the marker and were aligned exclusions.
+- **Go-like package:** `MultiplePackageError` and package scanning implement
+  conflicting selected declarations
+  ([`go/build/build.go`, lines 538–548 and 931–967](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/go/build/build.go#L538-L548));
+  `TestMultiplePackageImport` asserts the rule
+  ([`go/build/build_test.go`, lines 105–133](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/go/build/build_test.go#L105-L133)).
+  Both WW stages rejected an `alpha`/`beta` directory identically before tools.
+  This candidate was aligned.
+- **Go-like import:** `unusedImports` and `errorUnusedPkg` implement the unused
+  renamed-import diagnostic
+  ([`cmd/compile/internal/types2/resolver.go`, lines 706–740](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/cmd/compile/internal/types2/resolver.go#L706-L740));
+  official `importdecl0` asserts ordinary and renamed forms
+  ([lines 9–27](https://github.com/golang/go/blob/c19862e5f8415b4f24b189d065ed739517c548ba/src/internal/types/testdata/check/importdecl0/importdecl0a.go#L9-L27)).
+  After normalizing only PID-bearing scratch roots, both WW stages produced the
+  same unused-renamed-import diagnostic and no output. This candidate was
+  aligned.
+
+The command results in that list are directly measured WW behavior; the linked
+source and tests are behavior directly implemented or asserted by pinned Go.
+The conclusion that only test presentation changes while build, package, and
+import identity remain fixed is behavior derived from the pinned action and
+final-status placement.
+
+#### Ownership, final behavior, and preserved boundaries
+
+The directory owner is `internal/wwpackage.packagecommand`: its private
+explicit-target bit affects only final status, and `pkgemitplan`/`pkgemitgroup`
+record attributable build/run failure while preserving canonical result order.
+After all package captures, package results, install attempts, and temporary-root
+cleanup, the coordinator emits one final line. Attributable setup/load rejection
+uses the same status helper. The two public drivers own the raw-file equivalent:
+they remember the producer or process result, finish their existing cleanup,
+then emit the line. A successful run followed only by install or cleanup failure
+does not acquire test-failure status.
+
+Loading and source selection, canonical package and import identity, graph
+nodes, action construction, scheduling, compiler/assembler/linker invocation,
+generated main, child argv/environment/cwd/stdin, capture bytes, package
+diagnostics, and diagnostic precedence are unchanged. Runtime nonzero exit,
+signal, timeout, and executable-start failure keep their existing
+classification; only the command status line follows. One command-global bit
+is isolated from every product-local capture, so parallel completion order
+cannot duplicate or reorder it. If the coordinator itself is interrupted before
+final emission no post-termination output is promised; an observed child
+interruption is an ordinary run failure.
+
+Artifact construction and bytes are unchanged. A failing running-retained test
+still preserves prior public bytes and creates no new executable; successful
+products in a mixed request retain their existing independent install results.
+Producer failure, publication rejection, transaction rollback, cleanup, and
+residue ownership are unchanged, and the marker creates no file. Physical
+directories and the private explicit-target signal do not enter package,
+import, graph, action, artifact, symbol, `.wwi`, publication, or persistence
+identity. No persisted byte or key changed, so build workdir format remains
+`18`, test workdir format remains `19`, and semantic storage format remains `3`.
+
+The WW-native `explicit_test_failure_has_final_status` observer covers both
+stages for single and concurrent failing/succeeding packages, filters, list
+mode, raw files, setup/build and runtime failure, success, bare implicit and
+compile-only exclusions, running retained rollback, artifact-byte equality,
+diagnostic equality, exact cardinality/order, and `.new`/transaction cleanup.
+Existing directory execution observers cover signals, timeouts, child cleanup,
+and canonical-order behavior with the new final line, while build-mode controls
+prove that the other command axis remains silent.
+
 ## 12. Candidate architectures and hard-gate decision
 
 Five candidates were developed as coherent systems, not as feature bins.

docs/spec.md

@@ -790,6 +790,19 @@ linker, and other build failures retain their diagnostic standard-error
 channel; build-action stdout and stderr remain separate. Parallel products own
 independent captures and are still emitted in canonical product order.
 
+After those ordered results, an ordinary explicit `ww test` request that records
+an attributable setup, build, or execution failure emits exactly one standalone
+`FAIL\n` on standard output. The line is command-owned: it follows even a later
+successful package result, and a single explicit directory, recursive or dotted
+directory, or raw source file is sufficient. Runtime nonzero exit, signal,
+timeout, or executable-start failure all set that status. Filters, list mode,
+and the private execution of a retained test keep the same rule. Bare implicit
+current-directory `ww test`, `-c`, `-S`, build requests, CLI usage/shape or
+output preflight, publication-only failure, capture-only failure, cleanup-only
+failure, and later direct execution of a retained binary do not emit it. The
+marker changes no capture, diagnostic, executable, package/import/action
+identity, publication decision, or persistent byte.
+
 The coordinator does not change its own cwd or environment. Parallel products
 receive independent child environments and each uses its own source directory.
 Relative ordinary files, `testdata`, and writes resolve there for every

docs/test-system-v2.md

@@ -322,6 +322,18 @@ has a distinct capture, while canonical group-order emission remains
 byte-stable across `-j` values. Build-plan stdout and stderr stay distinct, and
 loader/build diagnostics stay on stderr.
 
+After canonical result emission, an ordinary test command with any explicit
+directory, recursive, dotted-directory, or raw-file target emits exactly one
+final standalone `FAIL\n` when attributable setup, build, or test execution
+failed. It follows later successful package output and applies to filters, list
+mode, signals, timeouts, executable-start failures, and running retained tests.
+The bare implicit-current-directory form, `-c`, `-S`, build requests, CLI
+usage/shape or output preflight, publication-only, capture-only, cleanup-only,
+and direct retained-binary execution do not receive the command marker.
+Directory coordination and both raw-file drivers own only this final
+presentation state; test captures, result trailers, diagnostics, scheduling,
+rollback, artifact bytes, and persisted action identity remain unchanged.
+
 The physical directory remains distinct from exact dotted package identity and
 from production, internal, external, recompiled, support, and generated-main
 action identity. Only product execution uses it. Compiler, assembler, archiver,