panic: munmap(7ff430e00000, 200000)) failed: function not implemented

DIAGNOSIS:
I0424 18:40:07.182225   62236 x:0] ***************************
I0424 18:40:07.182284   62236 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]
I0424 18:40:07.182297   62236 x:0] Version release-20190304.1-140-g99b877fa1d6f
I0424 18:40:07.182302   62236 x:0] PID: 62236
I0424 18:40:07.182329   62236 x:0] UID: 0, GID: 0
I0424 18:40:07.182332   62236 x:0] Configuration:
I0424 18:40:07.182335   62236 x:0] 		RootDir: /syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root
I0424 18:40:07.182349   62236 x:0] 		Platform: ptrace
I0424 18:40:07.182356   62236 x:0] 		FileAccess: shared, overlay: false
I0424 18:40:07.182361   62236 x:0] 		Network: host, logging: false
I0424 18:40:07.182366   62236 x:0] 		Strace: false, max size: 1024, syscalls: []
I0424 18:40:07.182371   62236 x:0] ***************************
D0424 18:40:07.182393   62236 x:0] Load container "/syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root" "ci-gvisor-ptrace-direct-overlay-host-2"
D0424 18:40:07.185726   62236 x:0] Signal container "ci-gvisor-ptrace-direct-overlay-host-2": signal 0
D0424 18:40:07.185760   62236 x:0] Signal sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0424 18:40:07.185765   62236 x:0] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0424 18:40:07.187404   62236 x:0] urpc: successfully marshalled 118 bytes.
I0424 18:40:07.576202   62236 x:0] Found sandbox "ci-gvisor-ptrace-direct-overlay-host-2", PID: 64306
I0424 18:40:07.576230   62236 x:0] Retrieving sandbox stacks
D0424 18:40:07.576319   62236 x:0] Stacks sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0424 18:40:07.576352   62236 x:0] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-2"
D0424 18:40:07.576442   62236 x:0] urpc: successfully marshalled 36 bytes.
W0424 18:40:07.641576   62236 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