diff --git a/cmd/cue/cmd/common.go b/cmd/cue/cmd/common.go
index 841c5a28c91..3e51f633443 100644
--- a/cmd/cue/cmd/common.go
+++ b/cmd/cue/cmd/common.go
@@ -19,7 +19,6 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
-	"strconv"
 	"strings"
 
 	"github.com/spf13/pflag"
@@ -33,7 +32,6 @@ import (
 	"cuelang.org/go/cue/parser"
 	"cuelang.org/go/cue/token"
 	"cuelang.org/go/internal"
-	"cuelang.org/go/internal/core/adt"
 	"cuelang.org/go/internal/encoding"
 	"cuelang.org/go/internal/filetypes"
 )
@@ -504,8 +502,6 @@ func parseArgs(cmd *Command, args []string, cfg *config) (p *buildPlan, err erro
 		return nil, err
 	}
 
-	adt.DebugSort, _ = strconv.Atoi(os.Getenv("CUE_DEBUG_SORT_ARCS"))
-
 	builds := loadFromArgs(args, cfg.loadCfg)
 	if builds == nil {
 		return nil, errors.Newf(token.NoPos, "invalid args")
diff --git a/internal/core/adt/context.go b/internal/core/adt/context.go
index a0b3343e057..8311fb0d391 100644
--- a/internal/core/adt/context.go
+++ b/internal/core/adt/context.go
@@ -19,7 +19,6 @@ import (
 	"log"
 	"reflect"
 	"regexp"
-	"sort"
 	"strings"
 
 	"github.com/cockroachdb/apd/v3"
@@ -33,47 +32,6 @@ import (
 	"cuelang.org/go/internal/cuedebug"
 )
 
-// DebugSort specifies that arcs be sorted consistently between implementations.
-//
-//	0: default
-//	1: sort by Feature: this should be consistent between implementations where
-//		   there is no change in the compiler and indexing code.
-//	2: alphabetical
-//
-// TODO: move to DebugFlags
-var DebugSort int
-
-func DebugSortArcs(c *OpContext, n *Vertex) {
-	if n.IsList() {
-		return
-	}
-	switch a := n.Arcs; DebugSort {
-	case 1:
-		sort.SliceStable(a, func(i, j int) bool {
-			return a[i].Label < a[j].Label
-		})
-	case 2:
-		sort.SliceStable(a, func(i, j int) bool {
-			return a[i].Label.SelectorString(c.Runtime) <
-				a[j].Label.SelectorString(c.Runtime)
-		})
-	}
-}
-
-func DebugSortFields(c *OpContext, a []Feature) {
-	switch DebugSort {
-	case 1:
-		sort.SliceStable(a, func(i, j int) bool {
-			return a[i] < a[j]
-		})
-	case 2:
-		sort.SliceStable(a, func(i, j int) bool {
-			return a[i].SelectorString(c.Runtime) <
-				a[j].SelectorString(c.Runtime)
-		})
-	}
-}
-
 // Assert panics if the condition is false. Assert can be used to check for
 // conditions that are considers to break an internal variant or unexpected
 // condition, but that nonetheless probably will be handled correctly down the
diff --git a/internal/core/adt/eval.go b/internal/core/adt/eval.go
index 55180400aed..a179c58c821 100644
--- a/internal/core/adt/eval.go
+++ b/internal/core/adt/eval.go
@@ -809,10 +809,6 @@ func (n *nodeContext) checkClosed(state vertexStatus) bool {
 func (n *nodeContext) completeArcs(state vertexStatus) {
 	unreachableForDev(n.ctx)
 
-	if DebugSort > 0 {
-		DebugSortArcs(n.ctx, n.node)
-	}
-
 	if n.node.hasAllConjuncts || n.node.Parent == nil {
 		n.node.setParentDone()
 	}
diff --git a/internal/core/adt/unify.go b/internal/core/adt/unify.go
index e263a7cf315..2745bd204a5 100644
--- a/internal/core/adt/unify.go
+++ b/internal/core/adt/unify.go
@@ -250,10 +250,6 @@ func (v *Vertex) unify(c *OpContext, needs condition, mode runMode) bool {
 		// done
 
 	case needs&subFieldsProcessed != 0:
-		if DebugSort > 0 {
-			DebugSortArcs(n.ctx, n.node)
-		}
-
 		switch {
 		case assertStructuralCycleV3(n):
 		// TODO: consider bailing on error if n.errs != nil.
diff --git a/internal/core/export/expr.go b/internal/core/export/expr.go
index 14c00c31768..cf456f8753d 100644
--- a/internal/core/export/expr.go
+++ b/internal/core/export/expr.go
@@ -189,20 +189,16 @@ func (x *exporter) mergeValues(label adt.Feature, src *adt.Vertex, a []conjunct,
 		return -cmp.Compare(f1, f2)
 	})
 
-	if adt.DebugSort == 0 {
-		m := sortArcs(extractFeatures(e.structs))
-		slices.SortStableFunc(fields, func(f1, f2 adt.Feature) int {
-			if m[f2] == 0 {
-				if m[f1] == 0 {
-					return +1
-				}
-				return -1
+	m := sortArcs(extractFeatures(e.structs))
+	slices.SortStableFunc(fields, func(f1, f2 adt.Feature) int {
+		if m[f2] == 0 {
+			if m[f1] == 0 {
+				return +1
 			}
-			return -cmp.Compare(m[f1], m[f2])
-		})
-	} else {
-		adt.DebugSortFields(e.ctx, fields)
-	}
+			return -1
+		}
+		return -cmp.Compare(m[f1], m[f2])
+	})
 
 	if len(e.fields) == 0 && !e.hasEllipsis {
 		switch len(e.embed) + len(e.conjuncts) {
diff --git a/internal/core/export/toposort.go b/internal/core/export/toposort.go
index b93716f380a..29c548f647a 100644
--- a/internal/core/export/toposort.go
+++ b/internal/core/export/toposort.go
@@ -32,11 +32,11 @@ func VertexFeatures(c *adt.OpContext, v *adt.Vertex) []adt.Feature {
 	if c.TopoSort {
 		return toposort.VertexFeatures(c, v)
 	} else {
-		return vertexFeatures(c, v)
+		return vertexFeatures(v)
 	}
 }
 
-func vertexFeatures(c *adt.OpContext, v *adt.Vertex) []adt.Feature {
+func vertexFeatures(v *adt.Vertex) []adt.Feature {
 	sets := extractFeatures(v.Structs)
 	m := sortArcs(sets) // TODO: use for convenience.
 
@@ -54,11 +54,7 @@ func vertexFeatures(c *adt.OpContext, v *adt.Vertex) []adt.Feature {
 		sets = append(sets, a)
 	}
 
-	a = sortedArcs(sets)
-	if adt.DebugSort > 0 {
-		adt.DebugSortFields(c, a)
-	}
-	return a
+	return sortedArcs(sets)
 }
 
 func extractFeatures(in []*adt.StructInfo) (a [][]adt.Feature) {
diff --git a/tools/flow/flow.go b/tools/flow/flow.go
index b417426a06f..71d8b6ab3c4 100644
--- a/tools/flow/flow.go
+++ b/tools/flow/flow.go
@@ -90,6 +90,7 @@ var (
 	// TODO: ErrUpdate: update and run a dependency, but don't complete a
 	// dependency as more results may come. This is useful in server mode.
 
+	// TODO: move CUE_DEBUG_TOOLS_FLOW=1 to e.g. CUE_DEBUG=toolsflow
 	debug = os.Getenv("CUE_DEBUG_TOOLS_FLOW") != ""
 )