memory leak with nested Exceptions

[inv2004]

Description

while true:
  try:
    try:
      raise newException(ValueError, "")
    except CatchableError:
      raise newException(ValueError, "") # or raise getCurrentException(), just raise works ok
  except ValueError:
    discard
  echo getOccupiedMem()

--mm:arc or --mm:refc - does not matter

Nim Version

• 2.0.0
• 1.6.14

Current Output

increased memory usage (visible in top too)

Expected Output

constant memory usage

Possible Solution

No response

Additional Information

It was suggested to check with -d:useMalloc. It made the getOccupiedMem to 0 (like it is ok), but top still shows growing rss

[ringabout]

The leak is caused a chain formed by the exceptions, which might indict that some logics related to popCurrentException are wrong. I'm gonna break the chain somehow.

[ringabout]

Related to #18070