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
an older Go version, the Go toolchain amends its defaults
to match that older Go version as closely as possible.
For example, when a Go 1.21 toolchain compiles a program,
if the work module's `go.mod` or the workspace's `go.work`

will succeed.
Such code should use a non-blocking receive instead.

These new behaviors are only enabled when the main Go program
is in a module with a `go.mod` `go` line using Go 1.23.0 or later.
When Go 1.23 builds older programs, the old behaviors remain in effect.
The new [GODEBUG setting](/doc/godebug) [`asynctimerchan=1`](/pkg/time/#NewTimer)
can be used to revert back to asynchronous channel behaviors

pkg compress/lzw, method (*Reader) Close() error
pkg compress/lzw, method (*Reader) Read([]uint8) (int, error)
pkg compress/lzw, method (*Reader) Reset(io.Reader, Order, int)
pkg compress/lzw, method (*Writer) Close() error
pkg compress/lzw, method (*Writer) Reset(io.Writer, Order, int)
pkg compress/lzw, method (*Writer) Write([]uint8) (int, error)
pkg compress/lzw, type Reader struct
pkg compress/lzw, type Writer struct

pkg syscall (windows-386), const XP1_GUARANTEED_DELIVERY = 2
pkg syscall (windows-386), const XP1_GUARANTEED_DELIVERY ideal-int
pkg syscall (windows-386), const XP1_GUARANTEED_ORDER = 4
pkg syscall (windows-386), const XP1_GUARANTEED_ORDER ideal-int
pkg syscall (windows-386), const XP1_IFS_HANDLES = 131072
pkg syscall (windows-386), const XP1_IFS_HANDLES ideal-int
pkg syscall (windows-386), const XP1_MESSAGE_ORIENTED = 8