updates and fixes to linters

.golangci.yml

@@ -29,6 +29,14 @@ linters:
   disable-all: true
 
 linters-settings:
+  govet:
+    enable:
+      - nilness
+      - unusedwrite
+  # enable-all: true
+  # disable:
+  #   - fieldalignment
+  #   - shadow
   depguard:
     rules:
       main:

cache/blobs_linux.go

@@ -80,10 +80,9 @@ func (sr *immutableRef) tryComputeOverlayBlob(ctx context.Context, lower, upper
 		if err := compressed.Close(); err != nil {
 			return emptyDesc, false, errors.Wrap(err, "failed to close compressed diff writer")
 		}
-		if labels == nil {
-			labels = map[string]string{}
+		labels = map[string]string{
+			labelspkg.LabelUncompressed: dgstr.Digest().String(),
 		}
-		labels[labelspkg.LabelUncompressed] = dgstr.Digest().String()
 	} else {
 		if err = overlay.WriteUpperdir(ctx, bufW, upperdir, lower); err != nil {
 			return emptyDesc, false, errors.Wrap(err, "failed to write diff")

hack/dockerfiles/lint.Dockerfile

@@ -4,7 +4,7 @@ ARG GO_VERSION=1.21
 ARG ALPINE_VERSION=3.19
 ARG XX_VERSION=1.4.0
 ARG PROTOLINT_VERSION=0.45.0
-ARG GOLANGCI_LINT_VERSION=1.55.0
+ARG GOLANGCI_LINT_VERSION=1.57.1
 
 FROM --platform=$BUILDPLATFORM golang:${GO_VERSION}-alpine${ALPINE_VERSION} AS golang-base
 FROM --platform=$BUILDPLATFORM yoheimuta/protolint:${PROTOLINT_VERSION} AS protolint-base
@@ -19,7 +19,7 @@ COPY --link --from=protolint-base /usr/local/bin/protolint /usr/local/bin/protol
 COPY --link --from=xx / /
 WORKDIR /go/src/github.com/moby/buildkit
 
-FROM base as golangci-lint
+FROM base AS golangci-lint
 ARG TARGETNAME
 ARG BUILDTAGS
 ARG TARGETPLATFORM
@@ -29,12 +29,12 @@ RUN --mount=target=/go/src/github.com/moby/buildkit \
   golangci-lint run --build-tags "${BUILDTAGS}" && \
   touch /golangci-lint.done
 
-FROM base as yamllint
+FROM base AS yamllint
 RUN --mount=target=/go/src/github.com/moby/buildkit \
   yamllint -c .yamllint.yml --strict . && \
   touch /yamllint.done
 
-FROM base as protolint
+FROM base AS protolint
 RUN --mount=target=/go/src/github.com/moby/buildkit \
   protolint lint . && \
   touch /protolint.done

source/git/source.go

@@ -440,9 +440,6 @@ func (gs *gitSourceHandler) Snapshot(ctx context.Context, g session.Group) (out
 	if err != nil {
 		return nil, err
 	}
-	if err != nil {
-		return nil, err
-	}
 	defer cleanup()
 	gitDir, err := git.GitDir(ctx)
 	if err != nil {

util/imageutil/config_test.go

@@ -39,7 +39,7 @@ func TestConfigMultiplatform(t *testing.T) {
 	pArm64 := platforms.MustParse("linux/arm64")
 	cfgDescArm64 := cc.Add(t, ocispecs.Image{Platform: pArm64}, ocispecs.MediaTypeImageConfig, nil)
 	mfstArm64 := ocispecs.Manifest{MediaType: ocispecs.MediaTypeImageManifest, Config: cfgDescArm64}
-	_, descArm64 := makeDesc(t, mfst386, mfstArm64.MediaType, &pArm64)
+	_, descArm64 := makeDesc(t, mfstArm64, mfstArm64.MediaType, &pArm64)
 
 	idx := ocispecs.Index{
 		MediaType: ocispecs.MediaTypeImageIndex,

util/overlay/overlay_linux.go

@@ -216,7 +216,7 @@ func Changes(ctx context.Context, changeFn fs.ChangeFunc, upperdir, upperdirView
 		} else if os.IsNotExist(err) || errors.Is(err, unix.ENOTDIR) {
 			// File doesn't exist in the base layer. Thus this is added.
 			kind = fs.ChangeKindAdd
-		} else if err != nil {
+		} else {
 			return errors.Wrap(err, "failed to stat base file during overlay diff")
 		}
 

util/system/path_test.go

@@ -90,7 +90,7 @@ func TestNormalizeWorkdir(t *testing.T) {
 func TestCheckSystemDriveAndRemoveDriveLetter(t *testing.T) {
 	// Fails if not C drive.
 	_, err := CheckSystemDriveAndRemoveDriveLetter(`d:\`, "windows")
-	if err == nil || (err != nil && err.Error() != "The specified path is not on the system drive (C:)") {
+	if err == nil || err.Error() != "The specified path is not on the system drive (C:)" {
 		t.Fatalf("Expected error for d:")
 	}