const golang.org/x/sys/unix.IPPROTO_GMTP

one use

	golang.org/x/sys/unix (current package)
		zerrors_darwin_arm64.go#L678: 	IPPROTO_GMTP                      = 0x64

The pages are generated with Golds v0.2.8-preview. (GOOS=darwin GOARCH=arm64)