fix: build --single-target (#4370)

closes #4369

cmd/build.go

@@ -22,6 +22,7 @@ import (
 	"github.com/goreleaser/goreleaser/pkg/config"
 	"github.com/goreleaser/goreleaser/pkg/context"
 	"github.com/spf13/cobra"
+	"golang.org/x/exp/slices"
 )
 
 type buildCmd struct {
@@ -236,18 +237,34 @@ func setupBuildSingleTarget(ctx *context.Context) {
 	if len(ctx.Config.Builds) == 0 {
 		ctx.Config.Builds = append(ctx.Config.Builds, config.Build{})
 	}
-	for i := range ctx.Config.Builds {
-		build := &ctx.Config.Builds[i]
+	var keep []config.Build
+	for _, build := range ctx.Config.Builds {
+		if !shouldBuild(build, goos, goarch) {
+			continue
+		}
 		build.Goos = []string{goos}
 		build.Goarch = []string{goarch}
 		build.Goarm = nil
 		build.Gomips = nil
 		build.Goamd64 = nil
 		build.Targets = nil
+		keep = append(keep, build)
 	}
+	ctx.Config.Builds = keep
 	ctx.Config.UniversalBinaries = nil
 }
 
+func shouldBuild(build config.Build, goos, goarch string) bool {
+	fmt.Println("AQUI", build)
+	if len(build.Targets) > 0 {
+		return slices.ContainsFunc(build.Targets, func(e string) bool {
+			return strings.HasPrefix(e, fmt.Sprintf("%s_%s", goos, goarch))
+		})
+	}
+	return slices.Contains(build.Goos, goos) &&
+		slices.Contains(build.Goarch, goarch)
+}
+
 func setupBuildID(ctx *context.Context, ids []string) error {
 	if len(ctx.Config.Builds) < 2 {
 		log.Warn("single build in config, '--id' ignored")

cmd/build_test.go

@@ -133,7 +133,17 @@ func TestSetupPipeline(t *testing.T) {
 
 func TestBuildFlags(t *testing.T) {
 	setup := func(opts buildOpts) *context.Context {
-		ctx := testctx.New()
+		ctx := testctx.NewWithCfg(config.Project{
+			Builds: []config.Build{
+				{
+					Goos:   []string{runtime.GOOS},
+					Goarch: []string{runtime.GOARCH},
+				},
+				{
+					Targets: []string{"linux_arm64"},
+				},
+			},
+		})
 		require.NoError(t, setupBuildContext(ctx, opts))
 		return ctx
 	}
@@ -186,6 +196,7 @@ func TestBuildFlags(t *testing.T) {
 
 		t.Run("runtime", func(t *testing.T) {
 			result := setup(opts)
+			require.Len(t, result.Config.Builds, 1)
 			require.Equal(t, []string{runtime.GOOS}, result.Config.Builds[0].Goos)
 			require.Equal(t, []string{runtime.GOARCH}, result.Config.Builds[0].Goarch)
 		})
@@ -194,6 +205,7 @@ func TestBuildFlags(t *testing.T) {
 			t.Setenv("GOOS", "linux")
 			t.Setenv("GOARCH", "arm64")
 			result := setup(opts)
+			require.Len(t, result.Config.Builds, 1)
 			require.Equal(t, []string{"linux"}, result.Config.Builds[0].Goos)
 			require.Equal(t, []string{"arm64"}, result.Config.Builds[0].Goarch)
 		})
@@ -306,6 +318,7 @@ func TestBuildSingleTargetWithSpecificTargets(t *testing.T) {
 	t.Setenv("GOOS", "darwin")
 	t.Setenv("GOARCH", "amd64")
 	setupBuildSingleTarget(ctx)
+	require.Len(t, ctx.Config.Builds, 1)
 	require.Equal(t, config.Build{
 		Goos:   []string{"darwin"},
 		Goarch: []string{"amd64"},
@@ -313,6 +326,26 @@ func TestBuildSingleTargetWithSpecificTargets(t *testing.T) {
 	require.Nil(t, ctx.Config.UniversalBinaries)
 }
 
+func TestBuildSingleTargetNoMatch(t *testing.T) {
+	ctx := testctx.NewWithCfg(config.Project{
+		ProjectName: "test",
+		Builds: []config.Build{
+			{
+				Goos:    []string{"linux", "darwin"},
+				Goarch:  []string{"amd64", "arm64"},
+				Goamd64: []string{"v1", "v2"},
+				Goarm:   []string{"6"},
+				Gomips:  []string{"anything"},
+			},
+		},
+	})
+
+	t.Setenv("GOOS", "windows")
+	t.Setenv("GOARCH", "amd64")
+	setupBuildSingleTarget(ctx)
+	require.Empty(t, ctx.Config.Builds)
+}
+
 func TestBuildSingleTargetRemoveOtherOptions(t *testing.T) {
 	ctx := testctx.NewWithCfg(config.Project{
 		ProjectName: "test",