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

<a href="#Order_of_evaluation">evaluation order</a>.
</p>

<p>
For struct literals the following rules apply:
</p>
<ul>
	<li>A key must be a field name declared in the struct type.
	</li>
	<li>An element list that does not contain any keys must
	    list an element for each struct field in the
	    order in which the fields are declared.
	</li>