ci: keep the GOOBJ link parity gate off the push pipeline

Assisted-by: GLM 5.3 Flash

.gitea/workflows/test.yml

@@ -119,18 +119,6 @@ jobs:
         # regression names the gate that failed instead of hiding inside the suite.
         run: go test -count=1 -timeout 10m -run 'TestGroundTruth' ./verify/...
 
-      - name: Install qemu-user
-        # The GOOBJ link regression runs the arm64 and riscv64 binaries it links
-        # under qemu-user; without the emulator those two degrade to link-only.
-        # The install is a no-op where it is already present.
-        run: dnf install -y qemu-user
-
-      - name: GOOBJ link parity
-        # The cmd/link parity gate: gasm objects substituted into a real go build
-        # must re-link on all four architectures, and the binaries must reproduce
-        # the toolchain baseline's output (native on amd64, qemu-user elsewhere).
-        run: go test -count=1 -timeout 10m -run 'TestGOOBJLinkRegression' ./verify/...
-
       - name: Coverage floor
         run: |
           perl -e '

justfile

@@ -62,6 +62,10 @@ unit pkgs=packages run=".*":
 fuzz target pkg fuzztime="60s":
     systemd-run --user --scope -p MemoryMax=4G -p MemorySwapMax=0 go test -run '^$' -fuzz '{{target}}' -fuzztime={{fuzztime}} {{pkg}}
 
+# The cmd/link GOOBJ parity gate, opt-in: the per-push pipeline cannot afford it.
+link-parity:
+    systemd-run --user --scope -p MemoryMax=4G -p MemorySwapMax=0 env GASM_LINK_PARITY=1 go test -count=1 -timeout 10m -run 'TestGOOBJLinkRegression' ./verify/
+
 # Benchmarks. On an idle machine only.
 bench pkgs=packages:
     go test -run '^$' -bench=. -benchmem -count=5 {{pkgs}}

verify/goobj_link_test.go

@@ -111,11 +111,18 @@ func fieldAfterLinkLog(line, flag string) string {
 }
 
 // TestGOOBJLinkRegression is the per-architecture end-to-end gate
-// described at the top of this file.
+// described at the top of this file.  It is a deliberate verification,
+// not a suite member: building the gasm binary and cross-linking a
+// module per architecture is minutes of work the shared one-core runner
+// beside the forge cannot afford on every push, so it runs opt-in, the
+// justfile's link-parity recipe being the intended way.
 func TestGOOBJLinkRegression(t *testing.T) {
 	if testing.Short() {
 		t.Skip("builds the gasm binary and links Go programs")
 	}
+	if os.Getenv("GASM_LINK_PARITY") == "" {
+		t.Skip("deliberate verification: set GASM_LINK_PARITY=1 (just link-parity)")
+	}
 	goBin, err := exec.LookPath("go")
 	if err != nil {
 		t.Skip("no Go toolchain available")