remove direct dependency on github/pkg/errors (#4970)

api/internal/accumulator/loadconfigfromcrds.go

@@ -7,11 +7,11 @@ import (
 	"encoding/json"
 	"strings"
 
-	"github.com/pkg/errors"
 	"k8s.io/kube-openapi/pkg/validation/spec"
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/internal/plugins/builtinconfig"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 	"sigs.k8s.io/kustomize/kyaml/resid"
 	"sigs.k8s.io/yaml"
@@ -39,7 +39,7 @@ func LoadConfigFromCRDs(
 		}
 		m, err := makeNameToApiMap(content)
 		if err != nil {
-			return nil, errors.Wrapf(err, "unable to parse open API definition from '%s'", path)
+			return nil, errors.WrapPrefixf(err, "unable to parse open API definition from '%s'", path)
 		}
 		otherTc, err := makeConfigFromApiMap(m)
 		if err != nil {

api/internal/builtins/HelmChartInflationGenerator.go

@@ -13,9 +13,9 @@ import (
 	"strings"
 
 	"github.com/imdario/mergo"
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/yaml"
 )
 
@@ -100,7 +100,7 @@ func (p *HelmChartInflationGeneratorPlugin) validateArgs() (err error) {
 	// ConfigHome is not loaded by the plugin, and can be located anywhere.
 	if p.ConfigHome == "" {
 		if err = p.establishTmpDir(); err != nil {
-			return errors.Wrap(
+			return errors.WrapPrefixf(
 				err, "unable to create tmp dir for HELM_CONFIG_HOME")
 		}
 		p.ConfigHome = filepath.Join(p.tmpDir, "helm")
@@ -144,7 +144,7 @@ func (p *HelmChartInflationGeneratorPlugin) runHelmCommand(
 	err := cmd.Run()
 	if err != nil {
 		helm := p.h.GeneralConfig().HelmConfig.Command
-		err = errors.Wrap(
+		err = errors.WrapPrefixf(
 			fmt.Errorf(
 				"unable to run: '%s %s' with env=%s (is '%s' installed?)",
 				helm, strings.Join(args, " "), env, helm),
@@ -207,7 +207,7 @@ func (p *HelmChartInflationGeneratorPlugin) writeValuesBytes(
 		return "", fmt.Errorf("cannot create tmp dir to write helm values")
 	}
 	path := filepath.Join(p.tmpDir, p.Name+"-kustomize-values.yaml")
-	return path, errors.Wrap(os.WriteFile(path, b, 0644), "failed to write values file")
+	return path, errors.WrapPrefixf(os.WriteFile(path, b, 0644), "failed to write values file")
 }
 
 func (p *HelmChartInflationGeneratorPlugin) cleanup() {

api/internal/builtins/PatchJson6902Transformer.go

@@ -7,11 +7,11 @@ import (
 	"fmt"
 
 	jsonpatch "github.com/evanphx/json-patch"
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/filters/patchjson6902"
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
 	"sigs.k8s.io/yaml"
 )
@@ -61,7 +61,7 @@ func (p *PatchJson6902TransformerPlugin) Config(
 	}
 	p.decodedPatch, err = jsonpatch.DecodePatch([]byte(p.JsonOp))
 	if err != nil {
-		return errors.Wrapf(err, "decoding %s", p.JsonOp)
+		return errors.WrapPrefixf(err, "decoding %s", p.JsonOp)
 	}
 	if len(p.decodedPatch) == 0 {
 		return fmt.Errorf(

api/internal/builtins/SortOrderTransformer.go

@@ -7,10 +7,10 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/resid"
 	"sigs.k8s.io/yaml"
 )
@@ -26,7 +26,7 @@ type SortOrderTransformerPlugin struct {
 
 func (p *SortOrderTransformerPlugin) Config(
 	_ *resmap.PluginHelpers, c []byte) error {
-	return errors.Wrap(yaml.Unmarshal(c, p), "Failed to unmarshal SortOrderTransformer config")
+	return errors.WrapPrefixf(yaml.Unmarshal(c, p), "Failed to unmarshal SortOrderTransformer config")
 }
 
 func (p *SortOrderTransformerPlugin) applyDefaults() {
@@ -69,7 +69,7 @@ func (p *SortOrderTransformerPlugin) Transform(m resmap.ResMap) (err error) {
 	p.applyDefaults()
 	err = p.validate()
 	if err != nil {
-		return errors.WithStack(err)
+		return err
 	}
 
 	// Sort
@@ -94,14 +94,14 @@ func applyOrdering(m resmap.ResMap, ordering []resid.ResId) error {
 	for i, id := range ordering {
 		resources[i], err = m.GetByCurrentId(id)
 		if err != nil {
-			return errors.Wrap(err, "expected match for sorting")
+			return errors.WrapPrefixf(err, "expected match for sorting")
 		}
 	}
 	m.Clear()
 	for _, r := range resources {
 		err = m.Append(r)
 		if err != nil {
-			return errors.Wrap(err, "SortOrderTransformer: Failed to append to resources")
+			return errors.WrapPrefixf(err, "SortOrderTransformer: Failed to append to resources")
 		}
 	}
 	return nil

api/internal/git/gitrunner.go

@@ -7,8 +7,8 @@ import (
 	"os/exec"
 	"time"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/internal/utils"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
 
@@ -24,7 +24,7 @@ type gitRunner struct {
 func newCmdRunner(timeout time.Duration) (*gitRunner, error) {
 	gitProgram, err := exec.LookPath("git")
 	if err != nil {
-		return nil, errors.Wrap(err, "no 'git' program on path")
+		return nil, errors.WrapPrefixf(err, "no 'git' program on path")
 	}
 	dir, err := filesys.NewTmpConfirmedDir()
 	if err != nil {
@@ -48,7 +48,7 @@ func (r gitRunner) run(args ...string) error {
 		func() error {
 			out, err := cmd.CombinedOutput()
 			if err != nil {
-				return errors.Wrapf(err, "failed to run '%s': %s", cmd.String(), string(out))
+				return errors.WrapPrefixf(err, "failed to run '%s': %s", cmd.String(), string(out))
 			}
 			return err
 		})

api/internal/plugins/compiler/compiler.go

@@ -12,8 +12,8 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/internal/plugins/utils"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 )
 
 // Compiler creates Go plugin object files.
@@ -86,7 +86,7 @@ func (b *Compiler) Compile() error {
 	cmd.Dir = b.workDir
 	if err := cmd.Run(); err != nil {
 		b.report()
-		return errors.Wrapf(
+		return errors.WrapPrefixf(
 			err, "cannot compile %s:\nSTDERR\n%s\n",
 			b.srcPath(), b.stderr.String())
 	}

api/internal/plugins/execplugin/execplugin.go

@@ -13,9 +13,9 @@ import (
 
 	"github.com/google/shlex"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/internal/plugins/utils"
 	"sigs.k8s.io/kustomize/api/resmap"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/yaml"
 )
 
@@ -151,17 +151,17 @@ func (p *ExecPlugin) Transform(rm resmap.ResMap) error {
 func (p *ExecPlugin) invokePlugin(input []byte) ([]byte, error) {
 	f, err := os.CreateTemp("", tmpConfigFilePrefix)
 	if err != nil {
-		return nil, errors.Wrap(
+		return nil, errors.WrapPrefixf(
 			err, "creating tmp plugin config file")
 	}
 	_, err = f.Write(p.cfg)
 	if err != nil {
-		return nil, errors.Wrap(
+		return nil, errors.WrapPrefixf(
 			err, "writing plugin config to "+f.Name())
 	}
 	err = f.Close()
 	if err != nil {
-		return nil, errors.Wrap(
+		return nil, errors.WrapPrefixf(
 			err, "closing plugin config file "+f.Name())
 	}
 	//nolint:gosec
@@ -175,7 +175,7 @@ func (p *ExecPlugin) invokePlugin(input []byte) ([]byte, error) {
 	}
 	result, err := cmd.Output()
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "failure in plugin configured via %s; %v",
 			f.Name(), err.Error())
 	}

api/internal/plugins/fnplugin/fnplugin.go

@@ -7,7 +7,7 @@ import (
 	"bytes"
 	"fmt"
 
-	"github.com/pkg/errors"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 
 	"sigs.k8s.io/kustomize/api/internal/plugins/utils"
 	"sigs.k8s.io/kustomize/api/resmap"
@@ -194,7 +194,7 @@ func (p *FnPlugin) invokePlugin(input []byte) ([]byte, error) {
 
 	err = p.runFns.Execute()
 	if err != nil {
-		return nil, errors.Wrap(
+		return nil, errors.WrapPrefixf(
 			err, "couldn't execute function")
 	}
 

api/internal/plugins/loader/loader.go

@@ -12,7 +12,6 @@ import (
 	"reflect"
 	"strings"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/internal/plugins/builtinhelpers"
 	"sigs.k8s.io/kustomize/api/internal/plugins/execplugin"
@@ -22,6 +21,7 @@ import (
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 	"sigs.k8s.io/kustomize/kyaml/resid"
 )
@@ -216,11 +216,11 @@ func (l *Loader) loadAndConfigurePlugin(
 	}
 	yaml, err := res.AsYAML()
 	if err != nil {
-		return nil, errors.Wrapf(err, "marshalling yaml from res %s", res.OrgId())
+		return nil, errors.WrapPrefixf(err, "marshalling yaml from res %s", res.OrgId())
 	}
 	err = c.Config(resmap.NewPluginHelpers(ldr, v, l.rf, l.pc), yaml)
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "plugin %s fails configuration", res.OrgId())
 	}
 	return c, nil
@@ -246,12 +246,12 @@ func (l *Loader) loadPlugin(res *resource.Resource) (resmap.Configurable, error)
 		// validation check that function mounts are under the current kustomization directory
 		for _, mount := range spec.Container.StorageMounts {
 			if filepath.IsAbs(mount.Src) {
-				return nil, errors.New(fmt.Sprintf("plugin %s with mount path '%s' is not permitted; "+
-					"mount paths must be relative to the current kustomization directory", res.OrgId(), mount.Src))
+				return nil, errors.Errorf("plugin %s with mount path '%s' is not permitted; "+
+					"mount paths must be relative to the current kustomization directory", res.OrgId(), mount.Src)
 			}
 			if strings.HasPrefix(filepath.Clean(mount.Src), "../") {
-				return nil, errors.New(fmt.Sprintf("plugin %s with mount path '%s' is not permitted; "+
-					"mount paths must be under the current kustomization directory", res.OrgId(), mount.Src))
+				return nil, errors.Errorf("plugin %s with mount path '%s' is not permitted; "+
+					"mount paths must be under the current kustomization directory", res.OrgId(), mount.Src)
 			}
 		}
 		return fnplugin.NewFnPlugin(&l.pc.FnpLoadingOptions), nil
@@ -307,11 +307,11 @@ func (l *Loader) loadGoPlugin(id resid.ResId, absPath string) (resmap.Configurab
 	log.Printf("Attempting plugin load from '%s'", absPath)
 	p, err := plugin.Open(absPath)
 	if err != nil {
-		return nil, errors.Wrapf(err, "plugin %s fails to load", absPath)
+		return nil, errors.WrapPrefixf(err, "plugin %s fails to load", absPath)
 	}
 	symbol, err := p.Lookup(konfig.PluginSymbol)
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "plugin %s doesn't have symbol %s",
 			regId, konfig.PluginSymbol)
 	}

api/internal/target/errmissingkustomization.go

@@ -7,8 +7,8 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/konfig"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 )
 
 type errMissingKustomization struct {
@@ -23,12 +23,8 @@ func (e *errMissingKustomization) Error() string {
 }
 
 func IsMissingKustomizationFileError(err error) bool {
-	_, ok := err.(*errMissingKustomization)
-	if ok {
-		return true
-	}
-	_, ok = errors.Cause(err).(*errMissingKustomization)
-	return ok
+	e := &errMissingKustomization{}
+	return errors.As(err, &e)
 }
 
 func NewErrMissingKustomization(p string) *errMissingKustomization {

api/internal/target/kusttarget.go

@@ -9,7 +9,6 @@ import (
 	"os"
 	"strings"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/internal/accumulator"
 	"sigs.k8s.io/kustomize/api/internal/builtins"
@@ -23,6 +22,7 @@ import (
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/openapi"
 	"sigs.k8s.io/yaml"
 )
@@ -195,11 +195,11 @@ func (kt *KustTarget) accumulateTarget(ra *accumulator.ResAccumulator) (
 	resRa *accumulator.ResAccumulator, err error) {
 	ra, err = kt.accumulateResources(ra, kt.kustomization.Resources)
 	if err != nil {
-		return nil, errors.Wrap(err, "accumulating resources")
+		return nil, errors.WrapPrefixf(err, "accumulating resources")
 	}
 	ra, err = kt.accumulateComponents(ra, kt.kustomization.Components)
 	if err != nil {
-		return nil, errors.Wrap(err, "accumulating components")
+		return nil, errors.WrapPrefixf(err, "accumulating components")
 	}
 	tConfig, err := builtinconfig.MakeTransformerConfig(
 		kt.ldr, kt.kustomization.Configurations)
@@ -208,17 +208,17 @@ func (kt *KustTarget) accumulateTarget(ra *accumulator.ResAccumulator) (
 	}
 	err = ra.MergeConfig(tConfig)
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "merging config %v", tConfig)
 	}
 	crdTc, err := accumulator.LoadConfigFromCRDs(kt.ldr, kt.kustomization.Crds)
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "loading CRDs %v", kt.kustomization.Crds)
 	}
 	err = ra.MergeConfig(crdTc)
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "merging CRDs %v", crdTc)
 	}
 	err = kt.runGenerators(ra)
@@ -235,7 +235,7 @@ func (kt *KustTarget) accumulateTarget(ra *accumulator.ResAccumulator) (
 	}
 	err = ra.MergeVars(kt.kustomization.Vars)
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "merging vars %v", kt.kustomization.Vars)
 	}
 	return ra, nil
@@ -265,7 +265,7 @@ func (kt *KustTarget) runGenerators(
 
 	gs, err = kt.configureExternalGenerators()
 	if err != nil {
-		return errors.Wrap(err, "loading generator plugins")
+		return errors.WrapPrefixf(err, "loading generator plugins")
 	}
 	generators = append(generators, gs...)
 	for i, g := range generators {
@@ -276,12 +276,12 @@ func (kt *KustTarget) runGenerators(
 		if resMap != nil {
 			err = resMap.AddOriginAnnotation(generators[i].Origin)
 			if err != nil {
-				return errors.Wrapf(err, "adding origin annotations for generator %v", g)
+				return errors.WrapPrefixf(err, "adding origin annotations for generator %v", g)
 			}
 		}
 		err = ra.AbsorbAll(resMap)
 		if err != nil {
-			return errors.Wrapf(err, "merging from generator %v", g)
+			return errors.WrapPrefixf(err, "merging from generator %v", g)
 		}
 	}
 	return nil
@@ -308,7 +308,7 @@ func (kt *KustTarget) configureExternalGenerators() (
 			}
 		}
 		if err = ra.AppendAll(rm); err != nil {
-			return nil, errors.Wrapf(err, "configuring external generator")
+			return nil, errors.WrapPrefixf(err, "configuring external generator")
 		}
 	}
 	ra, err := kt.accumulateResources(ra, generatorPaths)
@@ -355,7 +355,7 @@ func (kt *KustTarget) configureExternalTransformers(transformers []string) ([]*r
 		}
 
 		if err = ra.AppendAll(rm); err != nil {
-			return nil, errors.Wrapf(err, "configuring external transformer")
+			return nil, errors.WrapPrefixf(err, "configuring external transformer")
 		}
 	}
 	ra, err := kt.accumulateResources(ra, transformerPaths)
@@ -419,7 +419,7 @@ func (kt *KustTarget) accumulateResources(
 				if kusterr.IsMalformedYAMLError(errF) { // Some error occurred while tyring to decode YAML file
 					return nil, errF
 				}
-				return nil, errors.Wrapf(
+				return nil, errors.WrapPrefixf(
 					err, "accumulation err='%s'", errF.Error())
 			}
 			// store the origin, we'll need it later
@@ -436,7 +436,7 @@ func (kt *KustTarget) accumulateResources(
 				if kusterr.IsMalformedYAMLError(errF) { // Some error occurred while tyring to decode YAML file
 					return nil, errF
 				}
-				return nil, errors.Wrapf(
+				return nil, errors.WrapPrefixf(
 					err, "accumulation err='%s'", errF.Error())
 			}
 		}
@@ -478,7 +478,7 @@ func (kt *KustTarget) accumulateDirectory(
 	subKt := NewKustTarget(ldr, kt.validator, kt.rFactory, kt.pLdr)
 	err := subKt.Load()
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "couldn't make target for path '%s'", ldr.Root())
 	}
 	subKt.kustomization.BuildMetadata = kt.kustomization.BuildMetadata
@@ -513,12 +513,12 @@ func (kt *KustTarget) accumulateDirectory(
 		subRa, err = subKt.AccumulateTarget()
 	}
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "recursed accumulation of path '%s'", ldr.Root())
 	}
 	err = ra.MergeAccumulator(subRa)
 	if err != nil {
-		return nil, errors.Wrapf(
+		return nil, errors.WrapPrefixf(
 			err, "recursed merging from path '%s'", ldr.Root())
 	}
 	return ra, nil
@@ -528,21 +528,21 @@ func (kt *KustTarget) accumulateFile(
 	ra *accumulator.ResAccumulator, path string) error {
 	resources, err := kt.rFactory.FromFile(kt.ldr, path)
 	if err != nil {
-		return errors.Wrapf(err, "accumulating resources from '%s'", path)
+		return errors.WrapPrefixf(err, "accumulating resources from '%s'", path)
 	}
 	if kt.origin != nil {
 		originAnno, err := kt.origin.Append(path).String()
 		if err != nil {
-			return errors.Wrapf(err, "cannot add path annotation for '%s'", path)
+			return errors.WrapPrefixf(err, "cannot add path annotation for '%s'", path)
 		}
 		err = resources.AnnotateAll(utils.OriginAnnotationKey, originAnno)
 		if err != nil || originAnno == "" {
-			return errors.Wrapf(err, "cannot add path annotation for '%s'", path)
+			return errors.WrapPrefixf(err, "cannot add path annotation for '%s'", path)
 		}
 	}
 	err = ra.AppendAll(resources)
 	if err != nil {
-		return errors.Wrapf(err, "merging resources from '%s'", path)
+		return errors.WrapPrefixf(err, "merging resources from '%s'", path)
 	}
 	return nil
 }
@@ -553,7 +553,7 @@ func (kt *KustTarget) configureBuiltinPlugin(
 	if c != nil {
 		y, err = yaml.Marshal(c)
 		if err != nil {
-			return errors.Wrapf(
+			return errors.WrapPrefixf(
 				err, "builtin %s marshal", bpt)
 		}
 	}
@@ -562,7 +562,7 @@ func (kt *KustTarget) configureBuiltinPlugin(
 			kt.ldr, kt.validator, kt.rFactory, kt.pLdr.Config()),
 		y)
 	if err != nil {
-		return errors.Wrapf(
+		return errors.WrapPrefixf(
 			err, "trouble configuring builtin %s with config: `\n%s`", bpt, string(y))
 	}
 	return nil

api/internal/target/kusttarget_configplugin.go

@@ -7,12 +7,12 @@ import (
 	"fmt"
 	"path/filepath"
 
-	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/api/internal/plugins/builtinconfig"
 	"sigs.k8s.io/kustomize/api/internal/plugins/builtinhelpers"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
 
@@ -290,7 +290,7 @@ var transformerConfigurators = map[builtinhelpers.BuiltinPluginType]func(
 				if label.IncludeTemplates {
 					fss, err = fss.MergeAll(tc.TemplateLabels)
 					if err != nil {
-						return nil, errors.Wrap(err, "failed to merge template fieldSpec")
+						return nil, errors.WrapPrefixf(err, "failed to merge template fieldSpec")
 					}
 				}
 				// only add to metadata by default

api/internal/utils/errtimeout.go

@@ -7,7 +7,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/pkg/errors"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 )
 
 type errTimeOut struct {
@@ -24,13 +24,6 @@ func (e errTimeOut) Error() string {
 }
 
 func IsErrTimeout(err error) bool {
-	if err == nil {
-		return false
-	}
-	_, ok := err.(errTimeOut)
-	if ok {
-		return true
-	}
-	_, ok = errors.Cause(err).(errTimeOut)
-	return ok
+	e := &errTimeOut{}
+	return errors.As(err, &e)
 }