## Ports {#ports}

### Darwin {#darwin}

<!-- go.dev/issue/64207 -->
As [announced](go1.22#darwin) in the Go 1.22 release notes,
Go 1.23 requires macOS 11 Big Sur or later;
support for previous versions has been discontinued.

### Wasm {#wasm}

<!-- go.dev/issue/63718 -->
The `go_wasip1_wasm_exec` script in `GOROOT/misc/wasm` has dropped support

// memory backing the arena can be reused fairly quickly without garbage
// collection overhead. Applications must not call any method on this
// arena after it has been freed.
func (a *Arena) Free() {
	runtime_arena_arena_Free(a.a)
	a.a = nil
}

// New creates a new *T in the provided arena. The *T must not be used after

# That tree can be copied to a machine of the given target type
# and used as $GOROOT_BOOTSTRAP to bootstrap a local build.
#
# Only changes that have been committed to Git (at least locally,
# not necessary reviewed and submitted to master) are included in the tree.
#
# See also golang.org/x/build/cmd/genbootstrap, which is used
# to generate bootstrap tgz files for builders.

    validations:
      required: false

  - type: checkboxes
    id: related-idea
    attributes:
      label: "Related Idea"
      options:
        - label: "Has this idea, or one like it, been proposed before?"
        - label: "Does this affect error handling?"
        - label: "Is this about generics?"

Files in this directory are data for Go's API checker ("go tool api", in src/cmd/api).

Each file is a list of API features, one per line.

go1.txt (and similarly named files) are frozen once a version has been
shipped. Each file adds new lines but does not remove any.

except.txt lists features that may disappear without breaking true
compatibility.

Starting with go1.19.txt, each API feature line must end in "#nnnnn"

[time.Timer] and [time.Ticker].

First, `Timer`s and `Ticker`s that are no longer referred to by the program
become eligible for garbage collection immediately, even if their
`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

Second, the timer channel associated with a `Timer` or `Ticker` is

		if err != nil {
			t.Fatal(err)
		}
	}

	// The "pre" output should all have been flushed already.
	if want, got := pre, out.String(); want != got {
		t.Errorf("filter should have already flushed %q, but flushed %q", want, got)
	}

	code, err := f.Finish()
	if err != nil {
		t.Fatal(err)
	}

	// Nothing more should have been written to out.
	if want, got := pre, out.String(); want != got {

## Compiler {#compiler}

The build time overhead to building with [Profile Guided Optimization](/doc/pgo) has been reduced significantly.
Previously, large builds could see 100%+ build time increase from enabling PGO.
In Go 1.23, overhead should be in the single digit percentages.

## Assembler {#assembler}