Docker for Mac 起動中には Android Emulator (HAXM) が動かない
下記のようなエラーが出た場合で virtualbox そのものを使っている覚えがない場合で Docker for Mac を使っている場合は Android Emulatror の HAXM ありの場合に起動しない可能性がある。
Hax is enabled Hax ram_size 0x40000000 HAX is working and emulator runs in fast virt mode. emulator: Listening for console connections on port: 5554 emulator: Serial number of this emulator (for ADB): emulator-5554 Failed to sync vcpu reg Failed to sync vcpu reg Failed to sync vcpu reg emulator: ERROR: Unfortunately, there's an incompatibility between HAXM hypervisor and VirtualBox 4.3.30+ which doesn't allow multiple hypervisors to co-exist. It is being actively worked on; you can find out more about the issue at http://b.android.com/197915 (Android) and https://www.virtualbox.org/ticket/14294 (VirtualBox) Internal error: initial hax sync failed
https://forums.docker.com/t/cant-using-docker-for-mac-with-android-emulator-haxm/8939
対処方法は Docker for Mac を停止させるぐらいしか思いつかない。