go/src/runtime/debug/stack.go

// PrintStack prints to standard error the stack trace returned by runtime.Stack.
func PrintStack() { … }

// Stack returns a formatted stack trace of the goroutine that calls it.
// It calls [runtime.Stack] with a large enough buffer to capture the entire trace.
func Stack() []byte { … }

type CrashOptions …

// SetCrashOutput configures a single additional file where unhandled
// panics and other fatal errors are printed, in addition to standard error.
// There is only one additional file: calling SetCrashOutput again overrides
// any earlier call.
// SetCrashOutput duplicates f's file descriptor, so the caller may safely
// close f as soon as SetCrashOutput returns.
// To disable this additional crash output, call SetCrashOutput(nil).
// If called concurrently with a crash, some in-progress output may be written
// to the old file even after an overriding SetCrashOutput returns.
func SetCrashOutput(f *os.File, opts CrashOptions) error { … }

//go:linkname runtime_setCrashFD runtime.setCrashFD
func runtime_setCrashFD(uintptr) uintptr