Compare a build with the one the mesh registered, not the newest, which may be one put back (review of #336, hq issue 721)

internal/builder/check_builds.go

@@ -36,6 +36,10 @@ type CheckBuilding struct {
 	Publish Publisher
 	Scratch Scratch
 	Held    map[string]string
+	// Running is each artifact of the build the mesh has registered for its module, keyed "<module>/<artifact>"
+	// (novox/hq issue 721): what a build for the merge is compared with — never Held's newest build, which may be one
+	// its gate failed and the mesh put back.
+	Running map[string]string
 	Npmrc   Npmrc
 	Seats   map[string]string
 	// Named are the builds the build seat's verdicts of earlier checks of this pull request at this head name
@@ -179,7 +183,7 @@ func makeForTheMerge(ctx context.Context, run Runner, spec CheckSpec, with Check
 				if built.NotBuilt == "" {
 					// **Compared with what runs** (novox/hq issue 721): a failed comparison says nothing, and the
 					// module moves as before.
-					same, against, err := sameAsHeld(ctx, run, dir, b.Module, result.Built, with.Held)
+					same, against, err := sameAsHeld(ctx, run, dir, b.Module, result.Built, with.Running)
 					switch {
 					case err != nil:
 						say("build", "%s could not be compared with the build the mesh holds, so it moves: %v", b.Module, err)