Hi,
I don’t believe it turned out to be a permissions error. I’m posting the solution that worked for me below, in case it is ever of use to someone else.
First, I exported the same location as my previous code:
export SINGULARITYENV_TEMPLATEFLOW_HOME=/home/fmriprep/.cache/templateflow
Then in singularity, I binded a /opt directory, instead of the /fmriprep/.cache directory
singularity run --cleanenv -B /home/tun47039/work/tads_bids/archive/templateflow:/opt/templateflow
[fmriprep & arguments]
Not sure why this worked, but it did. I’m Running singularity 3.7.3 and fmriprep 20.2.6.