panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x99ed1a]

goroutine 166 [running]:
panic({0x11ef240, 0x210de40})
	GOROOT/src/runtime/panic.go:987 +0x3bb fp=0xc000b83018 sp=0xc000b82f58 pc=0x436a3b
runtime.panicmem(...)
	GOROOT/src/runtime/panic.go:260
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:837 +0x37d fp=0xc000b83078 sp=0xc000b83018 pc=0x44e05d
gvisor.dev/gvisor/pkg/sentry/kernel.(*ProcessGroup).SendSignal(0x0, 0xc000b83268)
	pkg/sentry/kernel/sessions.go:237 +0x5a fp=0xc000b83168 sp=0xc000b83078 pc=0x99ed1a
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*inputQueueTransformer).transform(0x6bdc5a, 0xc00039a180, 0xc00039a190, {0xc0009143c0?, 0xc000a0aa80?, 0x0?})
	pkg/sentry/fsimpl/devpts/line_discipline.go:402 +0x3c6 fp=0xc000b83398 sp=0xc000b83168 pc=0xd6e146
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).pushWaitBufLocked(0xc00039a190, 0xc000a0aa80?)
	pkg/sentry/fsimpl/devpts/queue.go:219 +0xce fp=0xc000b83400 sp=0xc000b83398 pc=0xd7104e
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*queue).write(0xc00039a190, {0x15f7018, 0xc000a0aa80}, {{0x15f1550, 0xc000a40000}, {0x0, 0x1, 0x20000140, 0x58}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/queue.go:183 +0x1f9 fp=0xc000b834b0 sp=0xc000b83400 pc=0xd70919
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*lineDiscipline).inputQueueWrite(0xc00039a180, {0x15f7018, 0xc000a0aa80}, {{0x15f1550, 0xc000a40000}, {0x0, 0x1, 0x20000140, 0x58}, {0x0, ...}})
	pkg/sentry/fsimpl/devpts/line_discipline.go:217 +0xcd fp=0xc000b83540 sp=0xc000b834b0 pc=0xd6d00d
gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts.(*masterFileDescription).Write(0x0?, {0x15f7018?, 0xc000a0aa80?}, {{0x15f1550, 0xc000a40000}, {0x0, 0x1, 0x20000140, 0x58}, {0x0, ...}}, ...)
	pkg/sentry/fsimpl/devpts/master.go:134 +0x65 fp=0xc000b835a0 sp=0xc000b83540 pc=0xd6f045
gvisor.dev/gvisor/pkg/sentry/vfs.(*FileDescription).Write(0xc000916380, {0x15f7018, 0xc000a0aa80}, {{0x15f1550, 0xc000a40000}, {0x0, 0x1, 0x20000140, 0x58}, {0x0, ...}}, ...)
	pkg/sentry/vfs/file_description.go:674 +0xa5 fp=0xc000b83620 sp=0xc000b835a0 pc=0x7738a5
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.write(0x15f7018?, 0xc000916380, {{0x15f1550, 0xc000a40000}, {0x0, 0x1, 0x20000140, 0x58}, {0x0, 0x1}}, ...)
	pkg/sentry/syscalls/linux/sys_read_write.go:347 +0x8e fp=0xc000b837f0 sp=0xc000b83620 pc=0xb416ae
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Write(0xc000a0aa80, {{0x3}, {0x20000140}, {0x58}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/syscalls/linux/sys_read_write.go:316 +0x25a fp=0xc000b83930 sp=0xc000b837f0 pc=0xb40e5a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc000a0aa80, 0x1, {{0x3}, {0x20000140}, {0x58}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:142 +0x80b fp=0xc000b83c70 sp=0xc000b83930 pc=0x9cb66b
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc000a0aa80, 0x0?, {{0x3}, {0x20000140}, {0x58}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:322 +0x54 fp=0xc000b83cd0 sp=0xc000b83c70 pc=0x9ccc54
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc00047e040?, 0xc000b83e18?, {{0x3}, {0x20000140}, {0x58}, {0x0}, {0x0}, {0x0}})
	pkg/sentry/kernel/task_syscall.go:282 +0x85 fp=0xc000b83d30 sp=0xc000b83cd0 pc=0x9cc845
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc000a08160?)
	pkg/sentry/kernel/task_syscall.go:257 +0x3ac fp=0xc000b83e28 sp=0xc000b83d30 pc=0x9cc50c
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc000916180?, 0xc000a0aa80)
	pkg/sentry/kernel/task_run.go:265 +0x144a fp=0xc000b83f60 sp=0xc000b83e28 pc=0x9be14a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc000a0aa80, 0x1c)
	pkg/sentry/kernel/task_run.go:94 +0x21c fp=0xc000b83fc0 sp=0xc000b83f60 pc=0x9bc65c
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start.func1()
	pkg/sentry/kernel/task_start.go:377 +0x2a fp=0xc000b83fe0 sp=0xc000b83fc0 pc=0x9c9aea
runtime.goexit()
	src/runtime/asm_amd64.s:1598 +0x1 fp=0xc000b83fe8 sp=0xc000b83fe0 pc=0x46d401
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:377 +0x105