The [GODEBUG History](#history) gives the exact defaults for each Go toolchain version.
For example, Go 1.21 introduces the `panicnil` setting,
controlling whether `panic(nil)` is allowed;
it defaults to `panicnil=0`, making `panic(nil)` a run-time error.
Using `panicnil=1` restores the behavior of Go 1.20 and earlier.

When compiling a work module or workspace that declares

func TestDontLoopForever(t *testing.T) {
	s := NewScanner(strings.NewReader("abc"))
	s.Split(loopAtEOFSplit)
	// Expect a panic
	defer func() {
		err := recover()
		if err == nil {
			t.Fatal("should have panicked")
		}
		if msg, ok := err.(string); !ok || !strings.Contains(msg, "empty tokens") {
			panic(err)
		}
	}()
	for count := 0; s.Scan(); count++ {
		if count > 1000 {
			t.Fatal("looping")
		}
	}

func TestNegativeRead(t *testing.T) {
	// should panic with a description pointing at the reader, not at itself.
	// (should NOT panic with slice index error, for example.)
	b := NewReader(new(negativeReader))
	defer func() {
		switch err := recover().(type) {
		case nil:
			t.Fatal("read did not panic")
		case error:

package tests_test

import (
	"testing"
	"gorm.io/gorm"
)

type Man struct {
	ID     int
	Age    int
	Name   string
	Detail string
}

// Panic-safe BeforeUpdate hook that checks for Changed("age")
func (m *Man) BeforeUpdate(tx *gorm.DB) (err error) {
	if !tx.Statement.Changed("age") {
		return nil
	}
	return nil
}

func TestSubModel(t *testing.T) {
	man := Man{Age: 18, Name: "random-name"}

package main

import (
	"go/ast"
	"go/token"
)

func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
	error_(token.NoPos, "unexpected type %T in walk", x)
	panic("unexpected type")
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return nil
}

func typeSpecTypeParams(n *ast.TypeSpec) *ast.FieldList {
	return nil

     *
     * @param pairs the list of AV pairs to modify
     * @param rep the replacement AV pair
     */
    public static void replace(final List<AvPair> pairs, final AvPair rep) {
        remove(pairs, rep.getType());
        pairs.add(rep);
    }

    /**
     * Encodes a list of AV pairs into byte array format
     *
     * @param pairs the list of AV pairs to encode
     * @return encoded avpairs

```
commit 4f3317effea38c203c358af9cb5ce3c0e4173976
Author: Klaus Post <******@****.***>
Date:   Mon Nov 8 08:41:27 2021 -0800

    Close stream on panic (#13605)

    Always close streamHTTPResponse on panic on main thread to avoid
    write/flush after response handler has returned.
```

```
λ git cherry-pick 4f3317effea38c203c358af9cb5ce3c0e4173976
```

    Iterable<String> list = Lists.newArrayList("cool", "pants");
    Iterator<String> iterator = list.iterator();
    assertEquals("pants", find(iterator, equalTo("pants")));
    assertFalse(iterator.hasNext());
  }

  public void testFind_notPresent() {
    Iterable<String> list = Lists.newArrayList("cool", "pants");
    Iterator<String> iterator = list.iterator();

//
// f(NewDummyDataGen(100, 0)) == f(NewDummyDataGen(50, 0)) + f(NewDummyDataGen(50, 50))
func NewDummyDataGen(totalLength, skipOffset int64) io.ReadSeeker {
	if totalLength < 0 {
		panic("Negative length passed to DummyDataGen!")
	}
	if skipOffset < 0 {
		panic("Negative rotations are not allowed")
	}

	skipOffset %= int64(len(alphabets))
	const multiply = 100
	as := bytes.Repeat(alphabets, multiply)

        pairs.add(flags1);
        pairs.add(timestamp);
        pairs.add(flags2);

        assertEquals(3, pairs.size(), "Should start with 3 pairs");

        AvPairs.remove(pairs, AvPair.MsvAvFlags);

        assertEquals(1, pairs.size(), "Should have 1 pair after removal");
        assertFalse(AvPairs.contains(pairs, AvPair.MsvAvFlags), "Should not contain MsvAvFlags");