panic: ptrace status unexpected: got 31, wanted stopped

goroutine 5461382 [running]:
DIAGNOSIS:
I0411 12:35:27.628365   47444 x:0] ***************************
I0411 12:35:27.628422   47444 x:0] Args: [/syzkaller/managers/ptrace-direct-overlay-host/current/image -root /syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root -watchdog-action=panic -network=none -debug -platform=ptrace -file-access=shared -network=host debug -stacks ci-gvisor-ptrace-direct-overlay-host-2]
I0411 12:35:27.628438   47444 x:0] Version release-20190304.1-112-g4209edafb6a9
I0411 12:35:27.628444   47444 x:0] PID: 47444
I0411 12:35:27.628450   47444 x:0] UID: 0, GID: 0
I0411 12:35:27.628462   47444 x:0] Configuration:
I0411 12:35:27.628471   47444 x:0] 		RootDir: /syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root
I0411 12:35:27.628475   47444 x:0] 		Platform: ptrace
I0411 12:35:27.628490   47444 x:0] 		FileAccess: shared, overlay: false
I0411 12:35:27.628499   47444 x:0] 		Network: host, logging: false
I0411 12:35:27.628515   47444 x:0] 		Strace: false, max size: 1024, syscalls: []
I0411 12:35:27.628519   47444 x:0] ***************************
D0411 12:35:27.628560   47444 x:0] Load container "/syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root" "ci-gvisor-ptrace-direct-overlay-host-2"
D0411 12:35:27.630628   47444 x:0] Signal container "ci-gvisor-ptrace-direct-overlay-host-2": signal 0
D0411 12:35:27.630676   47444 x:0] Signal sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0411 12:35:27.630683   47444 x:0] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0411 12:35:27.630833   47444 x:0] urpc: successfully marshalled 118 bytes.
I0411 12:35:27.971892   47444 x:0] Found sandbox "ci-gvisor-ptrace-direct-overlay-host-2", PID: 3736
I0411 12:35:27.971934   47444 x:0] Retrieving sandbox stacks
D0411 12:35:27.971939   47444 x:0] Stacks sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0411 12:35:27.971945   47444 x:0] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0411 12:35:27.972031   47444 x:0] urpc: successfully marshalled 36 bytes.
W0411 12:35:28.030490   47444 x:0] FATAL ERROR: retrieving stacks: getting sandbox "ci-gvisor-ptrace-direct-overlay-host-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer
retrieving stacks: getting sandbox "ci-gvisor-ptrace-direct-overlay-host-2" stacks: urpc method "debug.Stacks" failed: connection reset by peer