ENH: check for older fmriprep outputs

Author: mgxd

fmriprep/cli/run.py

@@ -490,7 +490,7 @@ def build_workflow(opts, retval):
     from bids import BIDSLayout
 
     from nipype import logging as nlogging, config as ncfg
-    from niworkflows.utils.bids import collect_participants
+    from niworkflows.utils.bids import collect_participants, check_pipeline_version
     from niworkflows.reports import generate_reports
     from ..__about__ import __version__
     from ..workflows.base import init_fmriprep_wf
@@ -522,6 +522,9 @@ def build_workflow(opts, retval):
         retval['return_code'] = 1
         return retval
 
+    # warn if older results exist
+    check_pipeline_version(__version__, output_dir / 'fmriprep' / 'dataset_description.json')
+
     if bids_dir in work_dir.parents:
         build_log.error(
             'The selected working directory is a subdirectory of the input BIDS folder. '