Fix exceptions for skims with compiled backend
reported here: https://gitlab.cern.ch/cp3-cms/bamboo/-/merge_requests/196/diffs#note_4844881 (thanks @swertz and @kjaffel !)
reported here: https://gitlab.cern.ch/cp3-cms/bamboo/-/merge_requests/196/diffs#note_4844881 (thanks @swertz and @kjaffel !)