ValueError: FITS header values must contain standard printable ASCII characters; "scopesim_templates.stellar.stars.star_grid

[carmeloarci]

The procedure saving the header of the fits file produced by scopesim when saving the output fails because of "/n" in the
keyword to be saved, the keyword regards the source. It may be any of the numerical SIM SRC0 xxxx entry.
....
print("Observe")
micado.observe(src_J)
print("Save")
hdus_J_small_test_3DM = micado.readout(filename= "scopesim_debug.fits")
...
In order to reproduce the error use the python script attached.

Traceback (most recent call last):
File "/python/simcado/MORFEO_debug.py", line 100, in
hdus_J_small_test_3DM = micado.readout(filename= "scopesim_debug.fits")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
MORFEO_debug.py.txt
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/scopesim/utils.py", line 1053, in wrapper
output = func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/scopesim/optics/optical_train.py", line 316, in readout
hdul = effect.apply_to(hdul, optical_train=self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/scopesim/effects/fits_headers.py", line 547, in apply_to
hdul = super().apply_to(hdul=hdul, optical_train=opt_train)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/scopesim/effects/fits_headers.py", line 286, in apply_to
hdul[i].header.update(resolved_with_counters)
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/astropy/io/fits/header.py", line 1087, in update
update_from_dict(k, v)
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/astropy/io/fits/header.py", line 1068, in update_from_dict
card = Card(k, v)
^^^^^^^^^^
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/astropy/io/fits/card.py", line 201, in init
self.value = value
^^^^^^^^^^
File "/home/carmelo/.conda/envs/scope_test/lib/python3.11/site-packages/astropy/io/fits/card.py", line 355, in value
raise ValueError(
ValueError: FITS header values must contain standard printable ASCII characters; "scopesim_templates.stellar.stars.star_grid(filter_name=J, amplitudes=[18.00751139 19.71896037 20.42893278 16.74155731 17.82481477 22.25630185\n 17.76112195 18.34062252 20.6108769 21.66227652 22.51209445 28.46949714\n 16.93850228 21.6801593 19.37519597 17.90536887 16.78798561 19.27439344\n

[hugobuddel]

This is the same error I got when running the script for #70 .

Also this can be worked around by disabling source_fits_keywords.

micado["source_fits_keywords"].include = False

A longer description is in #70. However, I think this used to work. I expect that there is a change in astropy that made this not work anymore. In the past, astropy verified the header only when saving the data. And the workaround we implemented (see #70) first created broken headers, and then patches them up before saving them. But it seems that now astropy checks the header when it is created; which is better, but breaks our workaround.

Apparently we don't have a proper test for this, so we should add that when fixing this bug.

[carmeloarci]

the fits header writer put the /n every 6 entries. Generating the error.
The work around works.

[carmeloarci]

I suggest to use as default the "False" case

micado["source_fits_keywords"].include = False

[hugobuddel]

Yeah, SourceDescriptionFitsKeywords should be turned off by default until we have proper tests for it so we can verify when it breaks (and we should fix it again). See AstarVienna/irdb#150