internal/buildgo: build Go with -force flag when available

Make builders and trybots more useful for broken and incomplete ports
by always including the '-force' flag when invoking make on a buildlet,
so that the build or trybot proceeds as far as it possibly can.

This CL is based on work done in CL 521356.

Fixes golang/go#61925.

Change-Id: I2a12f0a50cfce19f1e59f77e3cdf10241d2a2144
Co-authored-by: Joel Sing <[email protected]>
Reviewed-on: https://go-review.googlesource.com/c/build/+/535395
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Heschi Kreinick <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>

cmd/coordinator/buildstatus.go

@@ -598,11 +598,19 @@ func (st *buildStatus) SpanRecord(sp *schedule.Span, err error) *types.SpanRecor
 
 // goBuilder returns a GoBuilder for this buildStatus.
 func (st *buildStatus) goBuilder() buildgo.GoBuilder {
+	forceMake := true
+	if st.RevBranch == "release-branch.go1.20" {
+		// The concept of "broken ports" and -force flag didn't
+		// exist prior to Go 1.21. See go.dev/issue/56679.
+		// TODO: Remove this condition when Go 1.20 is no longer supported.
+		forceMake = false
+	}
 	return buildgo.GoBuilder{
 		Logger:     st,
 		BuilderRev: st.BuilderRev,
 		Conf:       st.conf,
 		Goroot:     "go",
+		Force:      forceMake,
 	}
 }
 
@@ -662,9 +670,9 @@ func (st *buildStatus) runAllSharded() (remoteErr, err error) {
 // buildTestPackages runs `go tool dist test -compile-only`, which builds all standard
 // library test packages but does not run any tests. Used in cross-compilation modes.
 func (st *buildStatus) buildTestPackages() (remoteErr, err error) {
-	if st.RevBranch == "release-branch.go1.19" || st.RevBranch == "release-branch.go1.20" {
-		// TODO(mknyszek): Go 1.19 and 1.20 don't support `go tool dist test -compile-only`
-		// very well. Remove this condition when Go 1.20 is no longer supported.
+	if st.RevBranch == "release-branch.go1.20" {
+		// Go 1.20 doesn't support `go tool dist test -compile-only` very well.
+		// TODO(mknyszek): Remove this condition when Go 1.20 is no longer supported.
 		return nil, nil
 	}
 	sp := st.CreateSpan("build_test_pkgs")

dashboard/builders.go

@@ -2122,8 +2122,6 @@ func init() {
 			// The machine is slow.
 			"GO_TEST_TIMEOUT_SCALE=5",
 		},
-		makeScriptArgs: []string{"-force"}, // Port is marked broken.
-		allScriptArgs:  []string{"-force"}, // Port is marked broken.
 	})
 	addBuilder(BuildConfig{
 		Name:         "openbsd-ppc64-n2vi",
@@ -2141,8 +2139,6 @@ func init() {
 		},
 		distTestAdjust: noTestDirAndNoReboot,
 		tryBot:         nil,
-		makeScriptArgs: []string{"-force"}, // Port is incomplete.
-		allScriptArgs:  []string{"-force"}, // Port is incomplete.
 	})
 	addBuilder(BuildConfig{
 		Name:         "openbsd-riscv64-jsing",
@@ -2164,8 +2160,6 @@ func init() {
 			// The machine is slow.
 			"GO_TEST_TIMEOUT_SCALE=3",
 		},
-		makeScriptArgs: []string{"-force"}, // Port is incomplete.
-		allScriptArgs:  []string{"-force"}, // Port is incomplete.
 	})
 	addBuilder(BuildConfig{
 		Name:           "netbsd-386-9_3",

internal/buildgo/buildgo.go

@@ -98,6 +98,9 @@ type GoBuilder struct {
 	// GorootBootstrap is an optional absolute Unix-style path to the
 	// bootstrap toolchain, overriding the default.
 	GorootBootstrap string
+	// Force controls whether to use the -force flag when building Go.
+	// See go.dev/issue/56679.
+	Force bool
 }
 
 // RunMake builds the tool chain.
@@ -111,11 +114,15 @@ func (gb GoBuilder) RunMake(ctx context.Context, bc buildlet.Client, w io.Writer
 	if gb.GorootBootstrap != "" {
 		env = append(env, "GOROOT_BOOTSTRAP="+gb.GorootBootstrap)
 	}
+	makeArgs := gb.Conf.MakeScriptArgs()
+	if gb.Force {
+		makeArgs = append(makeArgs, "-force")
+	}
 	remoteErr, err = bc.Exec(ctx, path.Join(gb.Goroot, gb.Conf.MakeScript()), buildlet.ExecOpts{
 		Output:   w,
 		ExtraEnv: env,
 		Debug:    true,
-		Args:     gb.Conf.MakeScriptArgs(),
+		Args:     makeArgs,
 	})
 	if err != nil {
 		makeSpan.Done(err)