--gc:arc segfaults when returning `result` from a proc

[n5m]

When returning result from a proc, --gc:arc fails while --gc:refc does not.

Example

type
  Wrapper = object
    discard

proc newWrapper(): ref Wrapper =
  new(result)

  # Uncommenting this line works with --gc:refc, fails with --gc:arc
  # Commenting this line works with --gc:refc and --gc:arc
  result

when isMainModule:
  let w: ref Wrapper = newWrapper()
  echo $w[]

Current Output

When result is uncommented

Compiling with nim compile --gc:arc return_result.nim

$ ./return_result 
Traceback (most recent call last)
/home/user/return_result.nim(15) return_result
SIGSEGV: Illegal storage access. (Attempt to read from nil?)

Compiling with nim compile --gc:refc return_result.nim

$ ./return_result 
()

When result is commented

No matter if you compile with --gc:arc or --gc:refc, both output the same.

$ ./return_result 
()

Expected Output

I expect to encounter a SIGSEGV in neither case.

Additional Information

git hash bdcd87a

$ nim --version
Nim Compiler Version 1.4.0 [Linux: amd64]
Compiled at 2020-10-16
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: bdcd87afca238a0a7b2c70971827cf9172817b12
active boot switches: -d:release