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

goroutine 498 [running]:
gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace.(*subprocess).Unmap(0xc420154d80, 0xa00000, 0x200000)
	pkg/sentry/platform/ptrace/subprocess.go:556 +0x51f
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).unmapASLocked(0xc420954c80, 0xa00000, 0xc00000)
	pkg/sentry/mm/address_space.go:217 +0xf9
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).breakCopyOnWriteLocked(0xc420954c80, 0xc4209552e8, 0x5, 0xa27000, 0xa28000, 0xa27000, 0xa28000, 0xc4209552e8, 0x5, 0xc4209552e8)
	pkg/sentry/mm/pma.go:449 +0xd25
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).getPMAsLocked(0xc420954c80, 0x10ec340, 0xc4204df600, 0xc420954cf0, 0x5, 0xa27000, 0xa28000, 0x1, 0xc420954cf0, 0x6, ...)
	pkg/sentry/mm/pma.go:142 +0x358
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).withInternalMappings(0xc420954c80, 0x10ec340, 0xc4204df600, 0xa27c10, 0xa27c14, 0x100, 0xc42036bce0, 0x1f772f0, 0x0, 0xc4203f07d0)
	pkg/sentry/mm/io.go:484 +0x274
gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).CopyOut(0xc420954c80, 0x10ec340, 0xc4204df600, 0xa27c10, 0xc4203f07d0, 0x4, 0x8, 0xec0100, 0x10d6174, 0x85, ...)
	pkg/sentry/mm/io.go:119 +0x210
gvisor.googlesource.com/gvisor/pkg/sentry/usermem.(*IOReadWriter).Write(0xc42036be18, 0xc4203f07d0, 0x4, 0x8, 0x1f772f0, 0xecabe0, 0x10d6174)
	pkg/sentry/usermem/usermem.go:155 +0x102
gvisor.googlesource.com/gvisor/pkg/sentry/usermem.CopyObjectOut(0x10ec340, 0xc4204df600, 0x10eaf00, 0xc420954c80, 0xa27c10, 0xecabe0, 0x10d6174, 0xc420480100, 0x46162c, 0x47ddc6, ...)
	pkg/sentry/usermem/usermem.go:184 +0x174
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).CopyOut(0xc4204df600, 0xa27c10, 0xecabe0, 0x10d6174, 0xc42036bf38, 0x88ed91, 0xc4204dfcc8)
	pkg/sentry/kernel/task_usermem.go:73 +0xaa
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*runExitMain).execute(0x0, 0xc4204df600, 0x10dd3c0, 0x0)
	pkg/sentry/kernel/task_exit.go:244 +0x301
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).run(0xc4204df600, 0x59)
	pkg/sentry/kernel/task_run.go:95 +0x265
created by gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:251 +0x194