It seems that the meas_date is not saved / read in correctly. There seems to be a regression of issue #4949 with latest master. Here is the code to reproduce:
import os.path as op
import mne
from mne.datasets import testing
data_path = testing.data_path()
raw_fname = op.join(data_path, 'MEG', 'sample',
'sample_audvis_trunc_raw.fif')
raw = mne.io.read_raw_fif(raw_fname)
raw.info['meas_date'] = None
raw.save('temp.fif')
raw2 = mne.io.read_raw_fif('temp.fif')
assert raw2.info['meas_date'] is NoneI discovered this while working on mne-tools/mne-bids#290
It seems that the
meas_dateis not saved / read in correctly. There seems to be a regression of issue #4949 with latest master. Here is the code to reproduce:I discovered this while working on mne-tools/mne-bids#290