panic: ptrace status unexpected: got 31, wanted stopped

goroutine 4108580 [running]:
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*thread).wait(0xc09301cff0, 0x0, 0x1545)
	pkg/sentry/platform/ptrace/subprocess.go:323 +0x3fb
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*thread).syscall(0xc09301cff0, 0xc003301820, 0xc0033019b8, 0x2, 0x2)
	pkg/sentry/platform/ptrace/subprocess.go:390 +0xc3
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*thread).syscallIgnoreInterrupt(0xc09301cff0, 0xc09301d000, 0xb, 0xc0033019b8, 0x2, 0x2, 0x0, 0x0, 0x0)
	pkg/sentry/platform/ptrace/subprocess.go:428 +0xc2
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*subprocess).syscall(0xc115f1a200, 0xb, 0xc0033019b8, 0x2, 0x2, 0x0, 0x0, 0x0)
	pkg/sentry/platform/ptrace/subprocess.go:562 +0xe8
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*subprocess).Unmap(0xc115f1a200, 0x2ad8888c8000, 0x1000)
	pkg/sentry/platform/ptrace/subprocess.go:602 +0x22e
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).unmapASLocked(0xc0034f8c80, 0x2ad8888c8000, 0x2ad8888c9000)
	pkg/sentry/mm/address_space.go:217 +0x73
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).MProtect(0xc0034f8c80, 0x2ad8888c8000, 0x1000, 0xc000000000, 0x0, 0x0)
	pkg/sentry/mm/syscalls.go:580 +0x446
gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux.Mprotect(0xc0030d8000, 0x2ad8888c8000, 0x1000, 0x0, 0x20022, 0x1, 0x1, 0x92dba4, 0xc003301c48, 0xc003301dd0, ...)
	pkg/sentry/syscalls/linux/sys_mmap.go:148 +0x73
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc0030d8000, 0xa, 0x2ad8888c8000, 0x1000, 0x0, 0x20022, 0x1, 0x1, 0x2ad8888c8000, 0xc373e0, ...)
	pkg/sentry/kernel/task_syscall.go:165 +0x30a
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc0030d8000, 0xa, 0x2ad8888c8000, 0x1000, 0x0, 0x20022, 0x1, 0x1, 0x1, 0x1)
	pkg/sentry/kernel/task_syscall.go:283 +0x69
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc0030d8000, 0xa, 0x2ad8888c8000, 0x1000, 0x0, 0x20022, 0x1, 0x1, 0xd12980, 0xc003301e58)
	pkg/sentry/kernel/task_syscall.go:244 +0x99
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc0030d8000, 0x2, 0xc115f1a200)
	pkg/sentry/kernel/task_syscall.go:219 +0x142
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*runApp).execute(0x0, 0xc0030d8000, 0xd12980, 0x0)
	pkg/sentry/kernel/task_run.go:215 +0xfda
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).run(0xc0030d8000, 0xb3b6)
	pkg/sentry/kernel/task_run.go:91 +0x149
created by gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:279 +0xfe