// Using After(10ms) but waiting for 500ms to read the channel
	// should produce a time from start+10ms, not start+500ms.
	// Make sure it does.
	// To avoid flakes due to very long scheduling delays,
	// require 10 failures in a row before deciding something is wrong.
	for range 10 {
		start := Now()
		c := After(10 * Millisecond)
		Sleep(500 * Millisecond)
		dt := (<-c).Sub(start)
		if dt < 400*Millisecond {
			return
		}

	}
}

func SkipFlakyNet(t testing.TB) {
	t.Helper()
	if v, _ := strconv.ParseBool(os.Getenv("GO_BUILDER_FLAKY_NET")); v {
		t.Skip("skipping test on builder known to have frequent network failures")
	}
}

// CPUIsSlow reports whether the CPU running the test is suspected to be slow.
func CPUIsSlow() bool {
	switch runtime.GOARCH {
	case "arm", "mips", "mipsle", "mips64", "mips64le", "wasm":

var a3, b3 /* ERROR "cycle" */ = int /* ERROR "assignment mismatch" */ /* ERROR "assignment mismatch" */ (1<<""[b3])

// issue10260
// Check that error messages explain reason for interface assignment failures.
type (
	I0 interface{}
	I1 interface{ foo() }
	I2 interface{ foo(x int) }
	T0 struct{}
	T1 struct{}
	T2 struct{}
)

func (*T1) foo() {}
func (*T2) foo(x int) {}

					// The test failed, which means it's possible the GOROOT copy
					// may have been modified. No choice but to reset it for next
					// module test case. (This is slow, but it happens only during
					// test failures.)
					gorootCopyDir = ""
				}
			}()

			rel, err := filepath.Rel(testenv.GOROOT(t), m.Dir)
			if err != nil {
				t.Fatalf("filepath.Rel(%q, %q): %v", testenv.GOROOT(t), m.Dir, err)
			}

		for x[i] = 1; x[i] <= byte(max); x[i]++ {
			testRec(t, x, i+1, max, numFail, build)
		}
		return
	}

	if !testSA(t, x, build) {
		*numFail++
		if *numFail >= 10 {
			t.Errorf("stopping after %d failures", *numFail)
			t.FailNow()
		}
	}
}

// testSA tests the suffix array build function on the input x.
// It constructs the suffix array and then checks that it is correct.

				if i := strings.LastIndex(name, "/"); i >= 0 {
					name = name[i+1:]
				}
				imp = NewPackage(path, name)
			}
			// continue to use the package as best as we can
			imp.fake = true // avoid follow-up lookup failures
		}
	}

	// package should be complete or marked fake, but be cautious
	if imp.complete || imp.fake {
		check.impMap[key] = imp
		// Once we've formatted an error message, keep the pkgPathMap

				if i := strings.LastIndex(name, "/"); i >= 0 {
					name = name[i+1:]
				}
				imp = NewPackage(path, name)
			}
			// continue to use the package as best as we can
			imp.fake = true // avoid follow-up lookup failures
		}
	}

	// package should be complete or marked fake, but be cautious
	if imp.complete || imp.fake {
		check.impMap[key] = imp
		// Once we've formatted an error message, keep the pkgPathMap

			}
			// Ensure that the replacement directory actually exists:
			// dirInModule does not report errors for missing modules,
			// so if we don't report the error now, later failures will be
			// very mysterious.
			if _, err := fsys.Stat(dir); err != nil {
				// TODO(bcmills): We should also read dir/go.mod here and check its Go version,
				// and return a gover.TooNewError if appropriate.

			continue
		}
		typesChecked++
		// ... we want to see a meaningful DW_AT_go_kind value.
		if val, ok := die.Val(intdwarf.DW_AT_go_kind).(int64); !ok || val == 0 {
			failures++
			// dump DIEs for first 10 failures.
			if failures <= 10 {
				idx := ex.IdxFromOffset(die.Offset)
				t.Logf("type DIE has DW_AT_go_runtime_type but invalid DW_AT_go_kind:\n")
				ex.DumpEntry(idx, false, 0)
			}

		}

		// Check for shadowing (a case that will never fire because
		// a previous case would have always fired first). This check
		// allows us to reorder concrete and interface cases.
		// (TODO: these should be vet failures, maybe?)
		for _, ic := range interfaceCases {
			// An interface type case will shadow all
			// subsequent types that implement that interface.
			if typecheck.Implements(c.typ.Type(), ic.typ.Type()) {