Error from changes in engine.py

[mmueller00]

I am getting an exception which is probably stemming from a change in the engine.py. It is either due to a new import (from torch.utils.tensorboard import SummaryWriter) or a change in the Engine class. See #1704

EXCEPTION
Traceback (most recent call last):
  File "/u/marten.mueller/dev/ctc_baseline/returnn/rnn.py", line 11, in <module>
    line: main()
    locals:
      main = <local> <function main at 0x755c7cb37ba0>
  File "/u/marten.mueller/dev/ctc_baseline/returnn/returnn/__main__.py", line 743, in main
    line: init(command_line_options=argv[1:])
    locals:
      init = <global> <function init at 0x755c7cb37880>
      command_line_options = <not found>
      argv = <local> ['/u/marten.mueller/dev/ctc_baseline/returnn/rnn.py', '/u/marten.mueller/dev/ctc_baseline/work/i6_core/returnn/training/ReturnnTrainingJob.jLl6e0M1VKU5/output/returnn.config'], _[0]: {len = 49}
  File "/u/marten.mueller/dev/ctc_baseline/returnn/returnn/__main__.py", line 456, in init
    line: with util.ReportImportedDevModules(description="RETURNN init"):
    locals:
      util = <global> <module 'returnn.util.basic' from '/u/marten.mueller/dev/ctc_baseline/returnn/returnn/util/basic.py'>
      util.ReportImportedDevModules = <global> <class 'returnn.util.basic.ReportImportedDevModules'>
      description = <not found>
  File "/u/marten.mueller/dev/ctc_baseline/returnn/returnn/util/basic.py", line 593, in ReportImportedDevModules.__exit__
    line: for mod_name, mod in sys.modules.items():
    locals:
      mod_name = <local> '__returnn_config__', len = 18
      mod = <local> <module '__returnn_config__' from '/u/marten.mueller/dev/ctc_baseline/work/i6_core/returnn/training/ReturnnTrainingJob.jLl6e0M1VKU5/output/returnn.config'>
      sys = <global> <module 'sys' (built-in)>
      sys.modules = <global> {'sys': <module 'sys' (built-in)>, 'builtins': <module 'builtins' (built-in)>, '_frozen_importlib': <module '_frozen_importlib' (frozen)>, '_imp': <module '_imp' (built-in)>, '_thread': <module '_thread' (built-in)>, '_warnings': <module '_warnings' (built-in)>, '_weakref': <module '_weakref' (bu..., len = 5494
      sys.modules.items = <global> <built-in method items of dict object at 0x755ca66e5380>
RuntimeError: dictionary changed size during iteration

[albertz]

Where do you have the from torch.utils.tensorboard import SummaryWriter? In your config?

I think the problem is clear then (anyway).

[albertz]

I pushed a fix. Can you test again?