panic: runtime error: invalid memory address or nil pointer dereference
DIAGNOSIS:
I0316 02:36:09.662773   60960 main.go:305] ***************************
I0316 02:36:09.662842   60960 main.go:306] Args: [/syzkaller/managers/main/current/image -root /syzkaller/managers/main/workdir/gvisor_root -watchdog-action=panic -network=none -debug -alsologtostderr -platform=ptrace -file-access=shared -network=none debug -stacks --ps ci-gvisor-main-3]
I0316 02:36:09.662889   60960 main.go:307] Version release-20200219.0-178-g97127750289b
I0316 02:36:09.662919   60960 main.go:308] PID: 60960
I0316 02:36:09.662948   60960 main.go:309] UID: 0, GID: 0
I0316 02:36:09.662974   60960 main.go:310] Configuration:
I0316 02:36:09.663002   60960 main.go:311] 		RootDir: /syzkaller/managers/main/workdir/gvisor_root
I0316 02:36:09.663036   60960 main.go:312] 		Platform: ptrace
I0316 02:36:09.663062   60960 main.go:313] 		FileAccess: shared, overlay: false
I0316 02:36:09.663110   60960 main.go:314] 		Network: none, logging: false
I0316 02:36:09.663141   60960 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0316 02:36:09.663172   60960 main.go:316] ***************************
D0316 02:36:09.665220   60960 container.go:159] Load container "/syzkaller/managers/main/workdir/gvisor_root" "ci-gvisor-main-3"
D0316 02:36:09.676761   60960 container.go:592] Signal container "ci-gvisor-main-3": signal 0
D0316 02:36:09.676819   60960 sandbox.go:814] Signal sandbox "ci-gvisor-main-3"
D0316 02:36:09.678653   60960 sandbox.go:318] Connecting to sandbox "ci-gvisor-main-3"
D0316 02:36:09.678838   60960 urpc.go:534] urpc: successfully marshalled 96 bytes.
I0316 02:36:09.906690   60960 debug.go:128] Found sandbox "ci-gvisor-main-3", PID: 60034
I0316 02:36:09.907256   60960 debug.go:137] Retrieving sandbox stacks
D0316 02:36:09.907304   60960 sandbox.go:932] Stacks sandbox "ci-gvisor-main-3"
D0316 02:36:09.907321   60960 sandbox.go:318] Connecting to sandbox "ci-gvisor-main-3"
W0316 02:36:09.907370   60960 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 60034: connection refused
retrieving stacks: connecting to control server at PID 60034: connection refused
W0316 02:36:09.907505   60960 main.go:338] Failure to execute command, err: 1