panic: munmap(a00000, 200000)) failed: function not implemented

goroutine 7248 [running]:
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*subprocess).Unmap(0xc4200f5680, 0xa00000, 0x200000)
	pkg/sentry/platform/ptrace/subprocess.go:556 +0x3c6
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).unmapASLocked(0xc420d14c80, 0xa00000, 0xc00000)
	pkg/sentry/mm/address_space.go:217 +0x74
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).breakCopyOnWriteLocked(0xc420d14c80, 0xc420d152e8, 0x4, 0xa24000, 0xa25000, 0xa24000, 0xa25000, 0xc420d152e8, 0x4, 0xc420d152e8)
	pkg/sentry/mm/pma.go:449 +0x8e5
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).getPMAsLocked(0xc420d14c80, 0xc74760, 0xc4205e1b00, 0xc420d14cf0, 0x4, 0xa24000, 0xa25000, 0x1, 0xc420d14cf0, 0x5, ...)
	pkg/sentry/mm/pma.go:142 +0x2a2
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).HandleUserFault(0xc420d14c80, 0xc74760, 0xc4205e1b00, 0xa24cf0, 0xc420000101, 0x7f2dfbc14dd0, 0xc4200f3140, 0x101)
	pkg/sentry/mm/syscalls.go:55 +0x194
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*runApp).execute(0x0, 0xc4205e1b00, 0xc67980, 0x0)
	pkg/sentry/kernel/task_run.go:235 +0x845
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).run(0xc4205e1b00, 0x722)
	pkg/sentry/kernel/task_run.go:95 +0x174
created by gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:251 +0x100