diff --git a/modules/mesh-build-go/cmd/mesh-build-go/integration_level_test.go b/modules/mesh-build-go/cmd/mesh-build-go/integration_level_test.go
index 8a791627..aa1cba11 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/integration_level_test.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/integration_level_test.go
@@ -6,6 +6,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 	"sync"
 	"testing"
@@ -345,14 +346,7 @@ func TestAStoreThatDoesNotStartEndsTheStepFailedAndLeavesNothing(t *testing.T) {
 	if f.busDir != "" && !f.busDown {
 		t.Errorf("the bus, started beside the store, was not stopped after the store failed")
 	}
-	var left []string
-	entries, _ := os.ReadDir(filepath.Join(m.Work, "ws1"))
-	for _, e := range entries {
-		if e.Name() != "slots" { // the ask's bound on processes, gone with the workspace (issue 1921, S10)
-			left = append(left, e.Name())
-		}
-	}
-	if len(left) != 1 || left[0] != "tree" {
+	if left := workspaceLeft(filepath.Join(m.Work, "ws1")); len(left) != 1 || left[0] != "tree" {
 		t.Errorf("the workspace holds %v, want only its tree", left)
 	}
 }
@@ -534,3 +528,16 @@ func TestTheIntegrationLevelRunsOnlyTheTestsItsTagsAdd(t *testing.T) {
 		t.Errorf("a tree with no tagged test started the store or ran go:\n%s", g.lines())
 	}
 }
+
+// workspaceLeft is what a workspace holds besides the directories its ask keeps there (askDirs: its cache layer and its
+// bound on processes, gone with the workspace; issue 1921, S2 and S10).
+func workspaceLeft(dir string) []string {
+	var left []string
+	entries, _ := os.ReadDir(dir)
+	for _, e := range entries {
+		if !slices.Contains(askDirs, e.Name()) {
+			left = append(left, e.Name())
+		}
+	}
+	return left
+}
diff --git a/modules/mesh-build-go/cmd/mesh-build-go/slots.go b/modules/mesh-build-go/cmd/mesh-build-go/slots.go
index 4c44d730..eca8a227 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/slots.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/slots.go
@@ -16,6 +16,13 @@ import (
 	"syscall"
 )
 
+// slotsDir is the directory in a workspace's root holding its slots.
+const slotsDir = "slots"
+
+// askDirs are the directories an ask keeps in its workspace's root beside its tree, gone with the workspace: its cache
+// layer and its bound on processes.
+var askDirs = []string{cacheLayerDir, slotsDir}
+
 // numCPU is the node's processor count.
 func numCPU() int { return runtime.NumCPU() }
 
@@ -31,7 +38,7 @@ var slotTurns atomic.Uint32
 
 // slots is the bound of the workspace's processes, m.parallel() slots.
 func (m *Module) slots(workspace string) slotPool {
-	return slotPool{dir: filepath.Join(m.Work, workspace, "slots"), n: m.parallel(), next: &slotTurns}
+	return slotPool{dir: filepath.Join(m.Work, workspace, slotsDir), n: m.parallel(), next: &slotTurns}
 }
 
 // acquire takes a slot of the pool, waiting for one when every slot is taken, and answers what frees it. A free slot is
diff --git a/modules/mesh-build-go/cmd/mesh-build-go/test_real_integration_test.go b/modules/mesh-build-go/cmd/mesh-build-go/test_real_integration_test.go
index 05175e99..e9377ec3 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/test_real_integration_test.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/test_real_integration_test.go
@@ -161,9 +161,8 @@ func TestIntegrationLevelRunsAgainstARealStoreAndBusAndLeavesNothing(t *testing.
 	if !res.Passed || res.Tests != 1 || res.Setup <= 0 || res.Setup > IntegrationSetup.Seconds() {
 		t.Errorf("result = %+v", res)
 	}
-	entries, _ := os.ReadDir(filepath.Join(work, "ws1"))
-	if len(entries) != 1 || entries[0].Name() != "tree" {
-		t.Errorf("the workspace holds %v, want only its tree: the run directory is gone", entries)
+	if left := workspaceLeft(filepath.Join(work, "ws1")); len(left) != 1 || left[0] != "tree" {
+		t.Errorf("the workspace holds %v besides the ask's own directories, want only its tree: the run directory is gone", left)
 	}
 	for deadline := time.Now().Add(5 * time.Second); len(processesNamed(work)) > 0 && time.Now().Before(deadline); time.Sleep(100 * time.Millisecond) {
 	}