Judge the SDK conformance fixtures against the SDK the controller pins, never a desktop's checkout (issue 449)

A check clones mesh-sdk beside the controller at the commit go.mod pins; elsewhere
the test reads a copy captured at that commit, held to go.mod. A missing clone fails
instead of skipping.

cmd/mesh-controller/checks.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"path"
+	"regexp"
+	"runtime/debug"
 	"slices"
 	"sort"
 	"strings"
@@ -246,9 +248,11 @@ func checkRequestFor(ctx context.Context, open *stores, p link.PullUpdated, scop
 		if dir == "mesh-controller" {
 			beside["mesh-controller-main"] = link.CheckedOut{Repository: url, Ref: refs["mesh-controller-main"]}
 			if e.Source.Seat != "" {
-				if lab, err := clone(inventory.Source{Seat: e.Source.Seat, Repository: siblingOf(e.Source.Repository,
-					"mesh-lab")}); err == nil {
-					beside["mesh-lab"] = link.CheckedOut{Repository: lab, Ref: refs["mesh-lab"]}
+				for _, sibling := range []string{"mesh-lab", "mesh-sdk"} {
+					if url, err := clone(inventory.Source{Seat: e.Source.Seat, Repository: siblingOf(e.Source.Repository,
+						sibling)}); err == nil {
+						beside[sibling] = link.CheckedOut{Repository: url, Ref: refs[sibling]}
+					}
 				}
 			}
 		}
@@ -271,17 +275,52 @@ func checkRequestFor(ctx context.Context, open *stores, p link.PullUpdated, scop
 // catalogue, whose checkout beside is what tests read its files from, at its main, what the next merge
 // builds from; and beside the controller its main, for a judge the running controller predates, and the
 // lab's main, whose replays every check runs. **One rule, read by the check the controller asks for and by
-// the facts snapshot** (Facts.Beside), so a check run by hand clones what the build seat clones.
+// the facts snapshot** (Facts.Beside), so a check run by hand clones what the build seat clones. Beside the
+// controller also the SDK, at the commit the controller's go.mod pins (sdkPinned): its conformance fixtures
+// are judged against the SDK the controller is built with, not one a desktop holds (novox/hq issue 449).
 func besideRefs(dir, running string) map[string]string {
 	switch dir {
 	case "mesh-catalog":
 		return map[string]string{dir: "main"}
 	case "mesh-controller":
-		return map[string]string{dir: running, "mesh-controller-main": "main", "mesh-lab": "main"}
+		return map[string]string{dir: running, "mesh-controller-main": "main", "mesh-lab": "main",
+			"mesh-sdk": sdkPinned()}
 	}
 	return map[string]string{dir: running}
 }
 
+// sdkModule is the Go module of the SDK the controller is built against.
+const sdkModule = "git.novox.be/novox/mesh-sdk/go"
+
+// pseudoCommit is the commit a Go pseudo-version names: v0.1.11-0.20261009143344-f047d0a4a970 → f047d0a4a970.
+var pseudoCommit = regexp.MustCompile(`-([0-9a-f]{12})$`)
+
+// sdkPinned is the ref of the SDK repository this controller was built from, as its go.mod pins it and its
+// build records it: a pseudo-version's commit, or a release's tag (the SDK tags its Go module under go/).
+// "main" only for a binary that records no SDK version — a local replace — which a running controller is
+// not (novox/hq issue 449).
+func sdkPinned() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "main"
+	}
+	for _, dep := range info.Deps {
+		if dep.Path != sdkModule {
+			continue
+		}
+		if dep.Replace != nil {
+			dep = dep.Replace
+		}
+		if m := pseudoCommit.FindStringSubmatch(dep.Version); m != nil {
+			return m[1]
+		}
+		if strings.HasPrefix(dep.Version, "v") {
+			return "go/" + dep.Version
+		}
+	}
+	return "main"
+}
+
 // siblingOf is another repository of the same owner: novox/mesh-controller → novox/mesh-lab.
 func siblingOf(repository, name string) string {
 	if cut := strings.LastIndex(repository, "/"); cut >= 0 {

cmd/mesh-controller/merge_gate_test.go

@@ -390,9 +390,10 @@ func TestAWithheldPathIsStoodInForByAPath(t *testing.T) {
 // controller's ask and by the facts — and finds the repository it checks from its origin.
 func TestACheckByHandClonesWhatTheSeatClones(t *testing.T) {
 	for dir, refs := range map[string]map[string]string{
-		"mesh-catalog":    {"mesh-catalog": "main"},
-		"mesh-host":       {"mesh-host": "c0ffee"},
-		"mesh-controller": {"mesh-controller": "c0ffee", "mesh-controller-main": "main", "mesh-lab": "main"},
+		"mesh-catalog": {"mesh-catalog": "main"},
+		"mesh-host":    {"mesh-host": "c0ffee"},
+		"mesh-controller": {"mesh-controller": "c0ffee", "mesh-controller-main": "main", "mesh-lab": "main",
+			"mesh-sdk": sdkPinnedByGoMod(t)},
 	} {
 		got := besideRefs(dir, "c0ffee")
 		for d, ref := range refs {
@@ -412,3 +413,24 @@ func TestACheckByHandClonesWhatTheSeatClones(t *testing.T) {
 		}
 	}
 }
+
+// sdkPinnedByGoMod is the SDK commit this tree's go.mod pins, read from the file rather than the build, so
+// sdkPinned is held to what the repository says (novox/hq issue 449).
+func sdkPinnedByGoMod(t *testing.T) string {
+	t.Helper()
+	raw, err := os.ReadFile(filepath.Join("..", "..", "go.mod"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, line := range strings.Split(string(raw), "\n") {
+		fields := strings.Fields(line)
+		if len(fields) >= 2 && fields[0] == sdkModule {
+			if m := pseudoCommit.FindStringSubmatch(fields[1]); m != nil {
+				return m[1]
+			}
+			return "go/" + fields[1]
+		}
+	}
+	t.Fatalf("go.mod requires no %s", sdkModule)
+	return ""
+}