build: improve error messages for docker driver

build/build.go

@@ -391,7 +391,7 @@ func toSolveOpt(ctx context.Context, node builder.Node, multiDriver bool, opt Op
 
 	for _, e := range opt.CacheTo {
 		if e.Type != "inline" && !nodeDriver.Features(ctx)[driver.CacheExport] {
-			return nil, nil, notSupported(nodeDriver, driver.CacheExport)
+			return nil, nil, notSupported(driver.CacheExport, nodeDriver, "https://docs.docker.com/go/build-cache-backends/")
 		}
 	}
 
@@ -529,7 +529,7 @@ func toSolveOpt(ctx context.Context, node builder.Node, multiDriver bool, opt Op
 	// set up exporters
 	for i, e := range opt.Exports {
 		if e.Type == "oci" && !nodeDriver.Features(ctx)[driver.OCIExporter] {
-			return nil, nil, notSupported(nodeDriver, driver.OCIExporter)
+			return nil, nil, notSupported(driver.OCIExporter, nodeDriver, "https://docs.docker.com/go/build-exporters/")
 		}
 		if e.Type == "docker" {
 			features := docker.Features(ctx, e.Attrs["context"])
@@ -555,7 +555,7 @@ func toSolveOpt(ctx context.Context, node builder.Node, multiDriver bool, opt Op
 					opt.Exports[i].Output = wrapWriteCloser(w)
 				}
 			} else if !nodeDriver.Features(ctx)[driver.DockerExporter] {
-				return nil, nil, notSupported(nodeDriver, driver.DockerExporter)
+				return nil, nil, notSupported(driver.DockerExporter, nodeDriver, "https:/docs.docker.com/go/build-exporters/")
 			}
 		}
 		if e.Type == "image" && nodeDriver.IsMobyDriver() {
@@ -627,7 +627,7 @@ func toSolveOpt(ctx context.Context, node builder.Node, multiDriver bool, opt Op
 			pp[i] = platforms.Format(p)
 		}
 		if len(pp) > 1 && !nodeDriver.Features(ctx)[driver.MultiPlatform] {
-			return nil, nil, notSupported(nodeDriver, driver.MultiPlatform)
+			return nil, nil, notSupported(driver.MultiPlatform, nodeDriver, "https://docs.docker.com/go/build-multi-platform/")
 		}
 		so.FrontendAttrs["platform"] = strings.Join(pp, ",")
 	}
@@ -1560,8 +1560,10 @@ func waitContextDeps(ctx context.Context, index int, results *waitmap.Map, so *c
 	return nil
 }
 
-func notSupported(d driver.Driver, f driver.Feature) error {
-	return errors.Errorf("%s feature is currently not supported for %s driver. Please switch to a different driver (eg. \"docker buildx create --use\")", f, d.Factory().Name())
+func notSupported(f driver.Feature, d driver.Driver, docs string) error {
+	return errors.Errorf(`%s is not supported for the %s driver.
+Switch to a different driver, or turn on the containerd image store, and try again.
+Learn more at %s`, f, d.Factory().Name(), docs)
 }
 
 func noDefaultLoad() bool {

driver/features.go

@@ -6,4 +6,4 @@ const OCIExporter Feature = "OCI exporter"
 const DockerExporter Feature = "Docker exporter"
 
 const CacheExport Feature = "Cache export"
-const MultiPlatform Feature = "Multiple platforms"
+const MultiPlatform Feature = "Multi-platform build"

tests/build.go

@@ -44,6 +44,9 @@ var buildTests = []func(t *testing.T, sb integration.Sandbox){
 	testBuildAnnotations,
 	testBuildBuildArgNoKey,
 	testBuildLabelNoKey,
+	testBuildCacheExportNotSupported,
+	testBuildOCIExportNotSupported,
+	testBuildMultiPlatformNotSupported,
 }
 
 func testBuild(t *testing.T, sb integration.Sandbox) {
@@ -376,3 +379,39 @@ func testBuildLabelNoKey(t *testing.T, sb integration.Sandbox) {
 	require.Error(t, err, string(out))
 	require.Equal(t, strings.TrimSpace(string(out)), `ERROR: invalid key-value pair "=TEST_STRING": empty key`)
 }
+
+func testBuildCacheExportNotSupported(t *testing.T, sb integration.Sandbox) {
+	if sb.Name() != "docker" {
+		t.Skip("skipping test for non-docker workers")
+	}
+
+	dir := createTestProject(t)
+	cmd := buildxCmd(sb, withArgs("build", "--cache-to=type=registry", dir))
+	out, err := cmd.CombinedOutput()
+	require.Error(t, err, string(out))
+	require.Contains(t, string(out), "Cache export is not supported")
+}
+
+func testBuildOCIExportNotSupported(t *testing.T, sb integration.Sandbox) {
+	if sb.Name() != "docker" {
+		t.Skip("skipping test for non-docker workers")
+	}
+
+	dir := createTestProject(t)
+	cmd := buildxCmd(sb, withArgs("build", fmt.Sprintf("--output=type=oci,dest=%s/result", dir), dir))
+	out, err := cmd.CombinedOutput()
+	require.Error(t, err, string(out))
+	require.Contains(t, string(out), "OCI exporter is not supported")
+}
+
+func testBuildMultiPlatformNotSupported(t *testing.T, sb integration.Sandbox) {
+	if sb.Name() != "docker" {
+		t.Skip("skipping test for non-docker workers")
+	}
+
+	dir := createTestProject(t)
+	cmd := buildxCmd(sb, withArgs("build", "--platform=linux/amd64,linux/arm64", dir))
+	out, err := cmd.CombinedOutput()
+	require.Error(t, err, string(out))
+	require.Contains(t, string(out), "Multi-platform build is not supported")
+}