Running lstchain_mc_r0_to_dl1 with default gamma_test_large.simtel.gz fails

[morcuended]

Running lstchain_mc_r0_to_dl1 with v0.10.11 and gave this error:

Downloading gamma_test_large.simtel.gz ...

Traceback (most recent call last):
  File "/fefs/aswg/software/conda/envs/lstchain-v0.10.11/bin/lstchain_mc_r0_to_dl1", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/fefs/aswg/software/conda/envs/lstchain-v0.10.11/lib/python3.11/site-packages/lstchain/scripts/lstchain_mc_r0_to_dl1.py", line 74, in main
    r0_to_dl1.r0_to_dl1(
  File "/fefs/aswg/software/conda/envs/lstchain-v0.10.11/lib/python3.11/site-packages/lstchain/reco/r0_to_dl1.py", line 352, in r0_to_dl1
    source = EventSource(input_url=input_filename,
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/fefs/aswg/software/conda/envs/lstchain-v0.10.11/lib/python3.11/site-packages/ctapipe/io/simteleventsource.py", line 512, in __init__
    self._subarray_info = self.prepare_subarray_info(
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/fefs/aswg/software/conda/envs/lstchain-v0.10.11/lib/python3.11/site-packages/ctapipe/io/simteleventsource.py", line 643, in prepare_subarray_info
    raise RuntimeError(
RuntimeError: `SimTelEventSource.focal_length_choice` was set to 'EFFECTIVE', but the effective focal length was not present in the file. Set `focal_length_choice='EQUIVALENT'` or make sure input files contain the effective focal length

[maxnoe]

Could be fixed by either

• Requiring an inputfile and not using the old prod3 file as default
• Changing the default file to gamma_prod5.simtel.zst which does have the effective focal length

[morcuended]

With this file gamma_prod5.simtel.zst I got No events in file

[maxnoe]

There might be no LST 1 events in there, I guess the default is aalowedtels=[1]?

[morcuended]

There might be no LST 1 events in there, I guess the default is aalowedtels=[1]?

yes, then I suggest to require the user explicitly an input file