panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xb68bee]

DIAGNOSIS:
I0316 02:18:30.952692   35053 main.go:305] ***************************
I0316 02:18:30.952846   35053 main.go:306] Args: [/syzkaller/managers/ptrace-proxy-sandbox-race/current/image -root /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root -watchdog-action=panic -network=none -debug -alsologtostderr -platform=ptrace -file-access=shared -network=sandbox -TESTONLY-unsafe-nonroot debug -stacks --ps ci-gvisor-ptrace-proxy-sandbox-race-1]
I0316 02:18:30.953072   35053 main.go:307] Version release-20200219.0-178-g97127750289b
I0316 02:18:30.953180   35053 main.go:308] PID: 35053
I0316 02:18:30.953316   35053 main.go:309] UID: 0, GID: 0
I0316 02:18:30.953392   35053 main.go:310] Configuration:
I0316 02:18:30.953481   35053 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0316 02:18:30.953620   35053 main.go:312] 		Platform: ptrace
I0316 02:18:30.953774   35053 main.go:313] 		FileAccess: shared, overlay: false
I0316 02:18:30.953912   35053 main.go:314] 		Network: sandbox, logging: false
I0316 02:18:30.954021   35053 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0316 02:18:30.954090   35053 main.go:316] ***************************
W0316 02:18:30.954216   35053 main.go:321] Block the TERM signal. This is only safe in tests!
D0316 02:18:30.954392   35053 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0316 02:18:30.963689   35053 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-1": signal 0
D0316 02:18:30.963847   35053 sandbox.go:814] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0316 02:18:30.963980   35053 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0316 02:18:30.964513   35053 urpc.go:534] urpc: successfully marshalled 117 bytes.
W0316 02:18:31.158685   35053 error.go:48] FATAL ERROR: container sandbox is not running
container sandbox is not running
W0316 02:18:31.159040   35053 main.go:338] Failure to execute command, err: 1