> We store all subject mris in a single directory, since they are often used
> across multiple experiments. Thus my subjects_dir never changes.

@Eric89GXL yes, same here, for some reason I got used to setting the subjects_dir whenever I start a new terminal session, otherwise it will just point to the $FREESURFER_HOME/subjects thanks to the Freeesurfer startup script:

export FREESURFER_HOME=/Applications/freesurfer
source $FREESURFER_HOME/FreeSurferEnv.sh