fn := q.PopLeft().Func

		// Check fn.
		if fn.WBPos.IsKnown() {
			var err strings.Builder
			call := funcs[fn]
			for call.target != nil {
				fmt.Fprintf(&err, "\n\t%v: called by %v", base.FmtPos(call.lineno), call.target.Nname)
				call = funcs[call.target]
			}
			// Seeing this error in a failed CI run? It indicates that
			// a function in the runtime package marked nowritebarrierrec

}

var traceIndent []byte

func tracePrint(title string, n ir.Node) func(np *ir.Node) {
	indent := traceIndent

	// guard against nil
	var pos, op string
	var tc uint8
	if n != nil {
		pos = base.FmtPos(n.Pos())
		op = n.Op().String()
		tc = n.Typecheck()
	}

	types.SkipSizeForTracing = true
	defer func() { types.SkipSizeForTracing = false }()
	fmt.Printf("%s: %s%s %p %s %v tc=%d\n", pos, indent, title, n, op, n, tc)

		s.m = make(map[string]src.XPos)
	}

	ls := typ.LinkString()
	if prev, ok := s.m[ls]; ok {
		base.ErrorfAt(pos, errors.DuplicateCase, "duplicate case %v in type switch\n\tprevious case at %s", typ, base.FmtPos(prev))
		return
	}
	s.m[ls] = pos

		if printed {
			fmt.Printf("\n")
		}

		// program listing, with individual effects listed

		if b == lv.f.Entry {
			live := lv.stackMaps[0]
			fmt.Printf("(%s) function entry\n", base.FmtPos(lv.fn.Nname.Pos()))
			fmt.Printf("\tlive=")
			printed = false
			for j, n := range lv.vars {
				if !live.Get(int32(j)) {
					continue
				}
				if printed {
					fmt.Printf(",")
				}

				// be more specific when the non-function
				// name matches a predeclared function
				base.Errorf("cannot call non-function %L, declared at %s",
					l, base.FmtPos(o.Name().Pos()))
			} else {
				base.Errorf("cannot call non-function %L", l)
			}
			n.SetType(nil)
			return n
		}
	}

	re(`-m(no-)?stack-(.+)`),
	re(`-mmacosx-(.+)`),
	re(`-mios-simulator-version-min=(.+)`),
	re(`-miphoneos-version-min=(.+)`),
	re(`-mlarge-data-threshold=[0-9]+`),
	re(`-mtvos-simulator-version-min=(.+)`),
	re(`-mtvos-version-min=(.+)`),
	re(`-mwatchos-simulator-version-min=(.+)`),
	re(`-mwatchos-version-min=(.+)`),
	re(`-mnop-fun-dllimport`),
	re(`-m(no-)?sse[0-9.]*`),
	re(`-m(no-)?ssse3`),

	if err != nil {
		t.Skip("failed to locate appletvos SDK, skipping")
	}
	CC := []string{
		"clang",
		"-arch",
		"arm64",
		"-isysroot", strings.TrimSpace(string(sdkPath)),
		"-mtvos-version-min=12.0",
		"-fembed-bitcode",
	}
	CGO_LDFLAGS := []string{"-framework", "CoreFoundation"}
	lib := filepath.Join("testdata", "testBuildFortvOS", "lib.go")
	tmpDir := t.TempDir()