kubectl SIGSEGV if k8s not running

[khk-globus]

What Happened?

I'm just getting going with Kubernetes, so trying out minikube. I was in the middle of downloading my first instance with:

$ minikube start --driver=docker
😄  minikube v1.25.1 on Ubuntu 20.04
✨  Using the docker driver based on user configuration
👍  Starting control plane node minikube in cluster minikube
🚜  Pulling base image ...
💾  Downloading Kubernetes v1.23.1 preload ...
    > gcr.io/k8s-minikube/kicbase: 378.98 MiB / 378.98 MiB  100.00% 76.80 KiB p
    > preloaded-images-k8s-v16-v1...: 128.42 MiB / 504.42 MiB  25.46% 88.93 Ki

Meanwhile, in another shell I attempted to list. Bad move apparently:

$ minikube kubectl -- get pods -A
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x4a8 pc=0x1a60f12]

goroutine 1 [running]:
k8s.io/minikube/cmd/minikube/cmd.glob..func23(0x3530580, {0xc000acc800, 0x3, 0x4})
	/app/cmd/minikube/cmd/kubectl.go:102 +0x8d2
github.com/spf13/cobra.(*Command).execute(0x3530580, {0xc000acc7c0, 0x4, 0x4})
	/go/pkg/mod/github.com/spf13/cobra@v1.3.0/command.go:860 +0x5f8
github.com/spf13/cobra.(*Command).ExecuteC(0x3532380)
	/go/pkg/mod/github.com/spf13/cobra@v1.3.0/command.go:974 +0x3bc
github.com/spf13/cobra.(*Command).Execute(...)
	/go/pkg/mod/github.com/spf13/cobra@v1.3.0/command.go:902
k8s.io/minikube/cmd/minikube/cmd.Execute()
	/app/cmd/minikube/cmd/root.go:157 +0xa31
main.main()
	/app/cmd/minikube/main.go:86 +0x255

This worked after the download finished, but a segfault is, well, a segfault. :-/

Attach the log file

$ minikube logs --file=log.txt
[nothing written here, and empty log file]

Operating System

Ubuntu

Driver

Docker

[afbjorklund]

Should be easy enough to add a guard against unknown version

[afbjorklund]

There was no error handling for cc.BinaryMirror, in 4a2c97f

@presztak

[presztak]

I'll fix this.

[presztak]

/assign