panic: munmap(7f8fff000000, 200000)) failed: function not implemented

DIAGNOSIS:
I1227 09:37:11.652327   23781 x:0] ***************************
I1227 09:37:11.652345   23781 x:0] 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-1]
I1227 09:37:11.652366   23781 x:0] Version release-20191213.0-49-g87e4d03fdf57
I1227 09:37:11.652374   23781 x:0] PID: 23781
I1227 09:37:11.652381   23781 x:0] UID: 0, GID: 0
I1227 09:37:11.652386   23781 x:0] Configuration:
I1227 09:37:11.652389   23781 x:0] 		RootDir: /syzkaller/managers/main/workdir/gvisor_root
I1227 09:37:11.652393   23781 x:0] 		Platform: ptrace
I1227 09:37:11.652397   23781 x:0] 		FileAccess: shared, overlay: false
I1227 09:37:11.652411   23781 x:0] 		Network: none, logging: false
I1227 09:37:11.652430   23781 x:0] 		Strace: false, max size: 1024, syscalls: []
I1227 09:37:11.652444   23781 x:0] ***************************
D1227 09:37:11.652481   23781 x:0] Load container "/syzkaller/managers/main/workdir/gvisor_root" "ci-gvisor-main-1"
D1227 09:37:11.654153   23781 x:0] Signal container "ci-gvisor-main-1": signal 0
D1227 09:37:11.654176   23781 x:0] Signal sandbox "ci-gvisor-main-1"
D1227 09:37:11.654182   23781 x:0] Connecting to sandbox "ci-gvisor-main-1"
D1227 09:37:11.654918   23781 x:0] urpc: successfully marshalled 96 bytes.
I1227 09:37:12.084797   23781 x:0] Found sandbox "ci-gvisor-main-1", PID: 16228
I1227 09:37:12.084913   23781 x:0] Retrieving sandbox stacks
D1227 09:37:12.084923   23781 x:0] Stacks sandbox "ci-gvisor-main-1"
D1227 09:37:12.084930   23781 x:0] Connecting to sandbox "ci-gvisor-main-1"
D1227 09:37:12.084994   23781 x:0] urpc: successfully marshalled 36 bytes.
W1227 09:37:12.213178   23781 x:0] FATAL ERROR: retrieving stacks: getting sandbox "ci-gvisor-main-1" stacks: urpc method "debug.Stacks" failed: connection reset by peer
retrieving stacks: getting sandbox "ci-gvisor-main-1" stacks: urpc method "debug.Stacks" failed: connection reset by peer
W1227 09:37:12.213280   23781 x:0] Failure to execute command, err: 1