}
		arg := call.Args[idx]
		pflag := calleeProps.ParamFlags[idx]
		if debugTrace&debugTraceScoring != 0 {
			fmt.Fprintf(os.Stderr, "=-= arg %d of %d: val %v flags=%s\n",
				idx, len(call.Args), arg, pflag.String())
		}

		if len(cs.ArgProps) == 0 {
			continue
		}
		argProps := cs.ArgProps[idx]

		if debugTrace&debugTraceScoring != 0 {
			fmt.Fprintf(os.Stderr, "=-= arg %d props %s value %v\n",

// expect to see this sequence of calls to Live/Kill:
//
//    abc:  Live(9), Kill(8), Live(6), Kill(0)
//    xyz:  Live(8), Kill(2)

import (
	"fmt"
	"os"
	"strings"
)

const debugtrace = false

// Interval hols the range [st,en).
type Interval struct {
	st, en int
}

// Intervals is a sequence of sorted, disjoint intervals.
type Intervals []Interval

func (i Interval) String() string {

}

func mainUsage() {
	help.PrintUsage(os.Stderr, base.Go)
	os.Exit(2)
}

func maybeStartTrace(pctx context.Context) context.Context {
	if cfg.DebugTrace == "" {
		return pctx
	}

	ctx, close, err := trace.Start(pctx, cfg.DebugTrace)
	if err != nil {
		base.Fatalf("failed to start trace: %v", err)
	}
	base.AtExit(func() {
		if err := close(); err != nil {

	tdcount++
	if err := os.Mkdir(dir, 0777); err != nil {
		t.Fatal(err)
	}
	defer tdmu.Unlock()
	return dir
}

const debugtrace = false

func gobuild(t *testing.T, indir string, bargs []string) {
	t.Helper()

	if debugtrace {
		if indir != "" {
			t.Logf("in dir %s: ", indir)
		}
		t.Logf("cmd: %s %+v\n", testenv.GoToolPath(t), bargs)
	}

	ModCacheRW bool   // -modcacherw flag
	ModFile    string // -modfile flag

	CmdName string // "build", "install", "list", "mod tidy", etc.

	DebugActiongraph  string // -debug-actiongraph flag (undocumented, unstable)
	DebugTrace        string // -debug-trace flag
	DebugRuntimeTrace string // -debug-runtime-trace flag (undocumented, unstable)

	// GoPathError is set when GOPATH is not set. it contains an
	// explanation why GOPATH is unset.

	cmd.Flag.Var((*buildvcsFlag)(&cfg.BuildBuildvcs), "buildvcs", "")

	// Undocumented, unstable debugging flags.
	cmd.Flag.StringVar(&cfg.DebugActiongraph, "debug-actiongraph", "", "")
	cmd.Flag.StringVar(&cfg.DebugTrace, "debug-trace", "", "")
	cmd.Flag.StringVar(&cfg.DebugRuntimeTrace, "debug-runtime-trace", "", "")
}

// AddCoverFlags adds coverage-related flags to "cmd". If the