panic: runtime error: index out of range [1] with length 0
DIAGNOSIS:
I0303 08:51:49.977785   55065 main.go:305] ***************************
I0303 08:51:49.977926   55065 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-3]
I0303 08:51:49.978119   55065 main.go:307] Version release-20200219.0-72-gce4d1e45bb88
I0303 08:51:49.978222   55065 main.go:308] PID: 55065
I0303 08:51:49.978313   55065 main.go:309] UID: 0, GID: 0
I0303 08:51:49.978386   55065 main.go:310] Configuration:
I0303 08:51:49.978528   55065 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0303 08:51:49.978617   55065 main.go:312] 		Platform: ptrace
I0303 08:51:49.978722   55065 main.go:313] 		FileAccess: shared, overlay: false
I0303 08:51:49.978840   55065 main.go:314] 		Network: sandbox, logging: false
I0303 08:51:49.978922   55065 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0303 08:51:49.979023   55065 main.go:316] ***************************
W0303 08:51:49.979100   55065 main.go:321] Block the TERM signal. This is only safe in tests!
D0303 08:51:49.980146   55065 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0303 08:51:49.989644   55065 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-3": signal 0
D0303 08:51:49.989793   55065 sandbox.go:806] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0303 08:51:49.989910   55065 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0303 08:51:49.992969   55065 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0303 08:51:52.159022   55065 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3", PID: 61546
I0303 08:51:52.159127   55065 debug.go:131] Retrieving sandbox stacks
D0303 08:51:52.170562   55065 sandbox.go:924] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0303 08:51:52.170727   55065 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
W0303 08:51:52.170925   55065 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 61546: connection refused
retrieving stacks: connecting to control server at PID 61546: connection refused
W0303 08:51:52.171366   55065 main.go:338] Failure to execute command, err: 1